Refactor and remove fakeMockNpm

[lukekarrys]

Refactor Config Reading During exec

This removes the previous workarounds that were required due to tests
setting configs that were not available in the constructor of the
commands.

This also made the fix for nodejs/node#45881
easier since the config checks for workspaces can now all be made in the
command. The fix was to move the package.json detection to
@npmcli/config and use that boolean instead of setting
location=project which affected all commands such as config set
saving to the wrong location.

Some notable changes from this refactor include:

• execWorkspaces no longer being passed the raw workspace filters and
  instead requiring this.setWorkspaces() to be called which was
  already being done in most commands
• static workspaces = [true|false] on all commands to indicate
  workspaces support. This is used in docs generation and whether to
  throw when execWorkspaces is called or not.

Drop fakeMockNpm and refactor mockNpm

This refactor also drops fakeMockNpm in favor of realMockNpm (now
just mockNpm), and adds new features to mockNpm.

Some new features of mockNpm:

• sets all configs via argv so they are parsed before npm.load(). This
  is the most important change as it more closely resembles real usage.
• automatically resets process.exitCode
• automatically puts global node_modules in correct testdir based on platform
• more helpful error messages when used in unsupported ways
• ability to preload a command for execution
• calls process.chdir automatically to prefix and sets globalPrefix to the
  specified global testdir

Misc Fixes

During the test refactor I uncovered some bugs that were also fixed or features
that were made easier to implement

• npm fund --which wasn't validated properly
• npm init -w path/ws was writng \\ separators to package.json on windows
• npm view now uses npm.output instead of console.log

Linting

This also removes some of the one off linting rules that were set in the
past to reduce churn and fixes all remaining errors.

Commits

• fix: evaluate configs in command class
• fix: generate workspace support for docs pages
• fix(fund): correctly parse and use which config
• fix: refactor help to use @npmcli/promise-spawn
• fix(init): write package.json workspaces paths with / separators
• fix(view): convert command to use output instead of console
• chore: convert ls test to mockNpm
• chore: convert diff test to mock npm and registry
• chore: convert all test to mockNpm
• chore: use chdir for mockNpm

[npm-cli-bot]

no statistically significant performance changes detected

timing results

app-large	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	64.374 ±1.72	27.540 ±0.08	33.623 ±11.07	29.234 ±1.48	4.426 ±0.05	4.798 ±0.29	3.644 ±0.01	17.564 ±0.15	3.602 ±0.10	5.420 ±0.17
#6014	63.720 ±6.17	27.238 ±0.16	34.394 ±13.34	28.792 ±0.26	4.382 ±0.10	4.669 ±0.01	3.481 ±0.09	17.847 ±0.24	3.446 ±0.04	5.251 ±0.50

app-medium	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	37.827 ±5.03	20.822 ±0.26	18.922 ±0.16	20.495 ±0.26	3.942 ±0.06	4.001 ±0.08	3.606 ±0.04	13.305 ±0.17	3.470 ±0.09	4.766 ±0.05
#6014	37.752 ±2.68	20.549 ±0.03	19.083 ±0.12	20.661 ±0.57	3.941 ±0.09	4.015 ±0.04	3.465 ±0.02	12.922 ±0.06	3.314 ±0.03	4.785 ±0.13

[lukekarrys]

Seeing as this refactor clocked in at +11k, -12k lines and is primarily test related, I'm going to merge this without review, since it would be very cumbersome to review at this point.

It also includes a fix for nodejs/node#45881 which would be nice to get in 9.2.1 for inclusion in the Node release slated for 2023-01-03.