The generate RPC method:

• was introduced in 2010
• is now only used for testing
• reaches across multiple components (wallet, mining)

I propose we remove the wallet generate RPC method and update all tests to use the generatetoaddress RPC method. We can do this non-invasively in the test framework by adding a generate method to TestNode so that the individual tests do not need to be updated. We could also add a generate alias to the generatetoaddress RPC method.

Doing this removes a wallet->server dependency and simplifies the wallet->server interface (#10973).

I'm opening this issue before implementing in case anyone has objections.