Clean up the mess that the code has become

[sureshjoshi]

After re-factoring and modifying the views, code needs some TLC

• Merged old branched code with updates, so repo doesn't get too stale while re-factoring #60
• Add standard githooks to repo #62
• Create GitHub test action #64
• Extract commands out of extension.ts and into separate file #67
• Land peek update which makes most functionality possible #68
• Re-write and test source-roots-provider #69
• Re-write and test targets-provider #70
• Re-write and test test-provider #72
• Add tests to all pants/* functions #73
• Test and cleanup LSP related code #106

[sureshjoshi]

Right now, I'm embedding a bunch of proof-of-concept code and testing out some UI concepts, which are not integrated with Pants - or require a Pants PR to be functional.

This will be a big, over-arching cleanup task.

[sureshjoshi]

This should probably be handled incrementally, or let's be honest, it'll never get done.