feat: run apex tests using the library

[AnanyaJha]

What does this PR do?

This PR adds the ability to run apex tests from the sidebar, code lens, and command palette using the Apex library

What issues does this PR fix or reference?

@W-7561367@

[codecov]

Codecov Report

Merging #2828 (37501a4) into develop (53329af) will increase coverage by 0.12%.
The diff coverage is 82.05%.

@@             Coverage Diff             @@
##           develop    #2828      +/-   ##
===========================================
+ Coverage    76.03%   76.15%   +0.12%     
===========================================
  Files          274      273       -1     
  Lines        10388    10453      +65     
  Branches      1185     1197      +12     
===========================================
+ Hits          7898     7961      +63     
+ Misses        2155     2151       -4     
- Partials       335      341       +6     

Impacted Files	Coverage Δ
...sforcedx-vscode-apex/src/codecoverage/colorizer.ts	72.50% <66.66%> (-3.56%)	⬇️
...rcedx-vscode-apex/src/views/testOutlineProvider.ts	65.16% <81.48%> (+2.04%)	⬆️
...de-apex/src/commands/forceApexTestRunCodeAction.ts	84.09% <88.23%> (+19.09%)	⬆️
...rcedx-vscode-core/src/commands/forceApexTestRun.ts	90.36% <88.46%> (+2.43%)	⬆️
...s/salesforcedx-vscode-apex/src/views/testRunner.ts	70.83% <100.00%> (ø)
...orcedx-vscode-core/src/commands/forceApexLogGet.ts	44.56% <100.00%> (ø)

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[AnanyaJha]

Since the LibraryCommandletExecutor currently lives in the core package, it uses the default Salesforce CLI channel from the channel services. If we switch to using the new channelService we have in the utils package right now, the experience is wonky because the Starting command.../Ending command... text appears in the default Salesforce CLI channel, while the output from the test run appears in the new channel that we've created. And since the command palette portion of the test:run functionality still lives in the core package as well, all the output from that command is displayed via the Salesforce CLI channel too

In a follow up PR, I think we should migrate the LibraryCommandletExecutor to the utils package, the Apex commands (test:run command) to the apex extension, and then switch this command to use the new channelService so it doesn't cause customers any confusion on which channel they should be looking at for apex test results

[lcampos]

Yes, that is part of the work we'll be doing in January to address some perf issues in the Apex extension.

[AnanyaJha]

reworked this executor a bit so that it could be used for the sidebar as well

[brpowell]

Ran through the various avenues for running tests with and without code coverage, library setting on and off:

• test sidebar
• codelens
• command palette

Looks good