…iple networks, add I2P peers

1b1088d test: add combined I2P/onion/localhost eviction protection tests (Jon Atack)
7c2284e test: add tests for inbound eviction protection of I2P peers (Jon Atack)
ce02dd1 p2p: extend inbound eviction protection by network to I2P peers (Jon Atack)
70bbc62 test: add combined onion/localhost eviction protection coverage (Jon Atack)
045cb40 p2p: remove unused m_is_onion member from NodeEvictionCandidate struct (Jon Atack)
310fab4 p2p: remove unused CompareLocalHostTimeConnected() (Jon Atack)
9e889e8 p2p: remove unused CompareOnionTimeConnected() (Jon Atack)
787d46b p2p: update ProtectEvictionCandidatesByRatio() doxygen docs (Jon Atack)
1e15acf p2p: make ProtectEvictionCandidatesByRatio() fully ratio-based (Jon Atack)
3f8105c test: remove combined onion/localhost eviction protection tests (Jon Atack)
38a81a8 p2p: add CompareNodeNetworkTime() comparator struct (Jon Atack)
4ee7aec p2p: add m_network to NodeEvictionCandidate struct (Jon Atack)
7321e6f p2p, refactor: rename vEvictionCandidates to eviction_candidates (Jon Atack)
ec590f1 p2p, refactor: improve constness in ProtectEvictionCandidatesByRatio() (Jon Atack)
4a19f50 test: add ALL_NETWORKS to test utilities (Jon Atack)
519e76b test: speed up and simplify peer_eviction_test (Jon Atack)
1cde800 p2p, refactor: rm redundant erase_size calculation in SelectNodeToEvict() (Jon Atack)

Pull request description:

  Continuing the work in bitcoin#20197 and bitcoin#20685, this pull updates and abstracts our inbound eviction protection to make it fully ratio-based and easily extensible to peers connected via high-latency privacy networks that we newly support, like I2P and perhaps others soon, as these peers are disadvantaged by the latency criteria of our eviction logic.

  It then adds eviction protection for peers connected over I2P.  As described in bitcoin#20685 (comment), we've observed over the past few months that I2P peers have a min ping latency similar to or greater than that of onion peers.

  The algorithm is a basically a multi-pass knapsack:

  - Count the number of eviction candidates in each of the disadvantaged
    privacy networks.

  - Sort the networks from lower to higher candidate counts, so that
    a network with fewer candidates will have the first opportunity
    for any unused slots remaining from the previous iteration.  In
    the case of a tie in candidate counts, priority is given by array
    member order from first to last, guesstimated to favor more unusual
    networks.

  - Iterate through the networks in this order.  On each iteration,
    allocate each network an equal number of protected slots targeting
    a total number of candidates to protect, provided any slots remain
    in the knapsack.

  - Protect the candidates in that network having the longest uptime,
    if any in that network are present.

  - Continue iterating as long as we have non-allocated slots
    remaining and candidates available to protect.

  The goal of this logic is to favorise the diversity of our peer connections.

  The individual commit messages describe each change in more detail.

  Special thank you to Vasil Dimov for the excellent review feedback and the algorithm improvement that made this change much better than it would have been otherwise. Thanks also to Antoine Riard, whose review feedback nudged this change to protect disadvantaged networks having fewer, rather than more, eviction candidates.

ACKs for top commit:
  laanwj:
    Code review re-ACK 1b1088d
  vasild:
    ACK 1b1088d

Tree-SHA512: 722f790ff11f2969c79e45a5e0e938d94df78df8687e77002f32e3ef5c72a9ac10ebf8c7a9eb7f71882c97ab0e67b2778191effdb747d9ca54d7c23c2ed19a90

…ionCandidatesByRatio()

b1d905c p2p: earlier continuation when no remaining eviction candidates (Vasil Dimov)
c9e8d8f p2p: process more candidates per protection iteration (Jon Atack)
02e411e p2p: iterate eviction protection only on networks having candidates (Jon Atack)
5adb064 bench: add peer eviction protection benchmarks (Jon Atack)
566357f refactor: move GetRandomNodeEvictionCandidates() to test utilities (Jon Atack)

Pull request description:

  This follow-up to #21261 improves `ProtectEvictionCandidatesByRatio()` for better performance.

  Benchmarks are added; the performance improvement is between 2x and 5x for the benchmarked cases (CPU 2.50GHz, Turbo off, performance mode, Debian Clang 11 non-debug build).

  ```
  $ ./src/bench/bench_bitcoin -filter="EvictionProtection*.*"
  ```

  The refactored code is well-covered by existing unit tests and also a fuzzer.

  - `$ ./src/test/test_bitcoin -t net_peer_eviction_tests`
  - `$ FUZZ=node_eviction ./src/test/fuzz/fuzz ../qa-assets/fuzz_seed_corpus/node_eviction`

ACKs for top commit:
  klementtan:
    Tested and code review ACK b1d905c.
  vasild:
    ACK b1d905c
  jarolrod:
    ACK b1d905c

Tree-SHA512: a3a6607b9ea2fec138da9780c03f63e177b6712091c5a3ddc3804b896a7585216446310280791f5e20cc023d02d2f03a4139237e12b5c1d7f2a1fa1011610e96

…P peers

Summary:
This pull updates and abstracts our inbound eviction protection to make it fully ratio-based and easily extensible to peers connected via high-latency privacy networks that we newly support, like I2P and perhaps others soon, as these peers are disadvantaged by the latency criteria of our eviction logic.

It then adds eviction protection for peers connected over I2P. We've observed over the past few months that I2P peers have a min ping latency similar to or greater than that of onion peers.

The algorithm is a basically a multi-pass knapsack:
 - Count the number of eviction candidates in each of the disadvantaged privacy networks.
 - Sort the networks from lower to higher candidate counts, so that a network with fewer candidates will have the first opportunity for any unused slots remaining from the previous iteration. In the case of a tie in candidate counts, priority is given by array member order from first to last, guesstimated to favor more unusual networks.
 - Iterate through the networks in this order. On each iteration, allocate each network an equal number of protected slots targeting a total number of candidates to protect, provided any slots remain in the knapsack.
 - Protect the candidates in that network having the longest uptime, if any in that network are present.
 - Continue iterating as long as we have non-allocated slots remaining and candidates available to protect.

The goal of this logic is to promote the diversity of our peer connections.

This is a backport of [[bitcoin/bitcoin#21261 | core#21261]]

Depends on D11042

Test Plan: `ninja all check-all`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11051

…JDNS peers

b7be28c test: add combined CJDNS/I2P/localhost/onion eviction protection tests (Jon Atack)
0a1bb84 test: add tests for inbound eviction protection of CJDNS peers (Jon Atack)
0c00c0c test: fix off-by-one logic in an eviction protection test (Jon Atack)
f7b8094 p2p: extend inbound eviction protection by network to CJDNS peers (Jon Atack)

Pull request description:

  Extend inbound eviction protection for peers connected over CJDNS, as is the case for peers connected via onion, localhost, and I2P since #21261 and #20197.  CJDNS peers seem to have better min ping latency than onion and I2P peers but still higher than that of unencrypted IPv4/6 peers and can be disadvantaged under our eviction criteria. They are also very few in number, which is a further reason to protect them, as the goal of this logic is to favorise the diversity of our peer connections.  CJDNS support was added in #23077 for the upcoming v23 release.

ACKs for top commit:
  laanwj:
    Concept and code review ACK b7be28c
  w0xlt:
    tACK b7be28c

Tree-SHA512: 89ebdd217602e16ae14b9bd0d5a25fc09f9b2384c951f820bc0f5a6d8452bbc9042065db817d5d5296c0ad22988491a83fc5b9a611e660c40ebd4f03448c4061