Improve LSP error reporting

[sgpthomas]

• [x] Actually run papercut, well-formed, and synthesis-papercut passes
• [x] support multiple errors in a single file
• [x] figure out what to do about primitive files that have no main component
• [x] Report parsing errors at reported location
• [x] handle errors that don't report location
• [x] add infrastructure for reporting warnings

[sgpthomas]

It's fun to flip through the error tests and see errors being reported.

https://github.com/calyxir/calyx/assets/3752122/949758e2-8a06-4e26-a1f5-9dd751d872af

[sampsyo]

Dang, this is awesome.

[rachitnigam]

@sgpthomas should we merge this?

[sgpthomas]

Yeah

[rachitnigam]

Push the big green button when ready!