* chore: initial prototype of net api from utility process

* chore: update url loader to work on both browser and utility processes

* chore: add net files to utility process bundle

* chore: re-add app ready check but only on main process

* chore: replace browser thread dcheck's with sequence checker

* refactor: move url loader from browser to common

* refactor: move net-client-request.ts from browser to common

* docs: add utility process to net api docs

* refactor: move net module app ready check to browser only

* refactor: switch import from main to common after moving to common

* test: add basic net module test for utility process

* refactor: switch browser pid with utility pid

* refactor: move electron_api_net from browser to common

* chore: add fetch to utility net module

* chore: add isOnline and online to utility net module

* refactor: move net spec helpers into helper file

* refactor: break apart net module tests

Adds two additional net module test files: `api-net-session-spec.ts` for
tests that depend on a session being available (aka depend on running on
the main process) and `api-net-custom-protocols-spec.ts` for custom
protocol tests. This enables running `api-net-spec.ts` in the utility
process.

* test: add utility process mocha runner to run net module tests

* docs: add utility process to net module classes

* refactor: update imports in lib/utility to use electron/utility

* chore: check browser context before using in main process

Since the browser context supplied to the SimpleURLLoaderWrapper can now
be null for use in the UtilityProcess, adding a null check for the main
process before use to get a more sensible error if something goes wrong.

Co-authored-by: Cheng Zhao <github@zcbenz.com>

* chore: remove test debugging

* chore: remove unnecessary header include

* docs: add utility process net module limitations

* test: run net module tests in utility process individually

* refactor: clean up prior utility process net tests

* chore: add resolveHost to utility process net module

* chore: replace resolve host dcheck with sequence checker

* test: add net module tests for net.resolveHost

* docs: remove utility process limitation for resolveHost

---------

Co-authored-by: deepak1556 <hop2deep@gmail.com>
Co-authored-by: Cheng Zhao <github@zcbenz.com>

Co-authored-by: Devraj Mehta <devm33@github.com>