chore: test using existing command

[WillieRuemmele]

What does this PR do?
adds a new command for generating a "basic" apex unit test, just the test class and annotation

What issues does this PR fix or reference?
@W-14709113@

Functionality Before
would have to generate an apex class with a large header comment, and test method

Functionality After
just generate a ready-to-go apex unit test

requires: forcedotcom/salesforcedx-templates#575
used by: https://github.com/forcedotcom/salesforcedx-vscode-einstein-gpt/pull/325

[peternhale]

@WillieRuemmele if I read this correctly, ED4will be calling the a command execute directly with the basic template name and if run from command palette, the command will use the decorated template.

If this is the case, I like it!

[WillieRuemmele]

correct, here's the accompanying PR in E4D

looks like the command name has changed since we first started with it anyways

[peternhale]

@WillieRuemmele Thanks for going the extra mile to avoid a new command. All that is missing are unit tests. Could you have a look here.

[WillieRuemmele]

@peternhale added tests, hard to get many assertions because everything was mocked. I thought this approach would have a lot of breaking changes, and be harder to integrate, glad it's easier this way

[floralan]

Good work!

✅ QA has passed.

1. This command should not be exposed in the command palette ✅
2. Confirm the unit test template generated by sfdx.apex.generate.unit.test.class doesn’t change ✅