Use simplified treesitter grammar and simplify error handling

[chappertron]

Lots of changes:

• Now uses the simplified, more inlined tree-sitter grammar (see)

• Error handling now follows a more standard format

• The language server now uses the same underlying structs as the CLI tool. No more duplication of work!

• New lints:

  • Can now check pair_styles provided
  • Checks if commands have been defined multiple times before a run command and warns if the case

[chappertron]

nvm there seems to be a lot of tests failing doh

[chappertron]

Now fixed the tests. lgtm