feat: migrate to Anteater API

[ecxyzzy]

This PR shouldn't have been necessary since in an ideal world we would have skipped API-Next, but oh well.

Summary

• Set up codegen for types using openapi-typescript, remove ppapi-next-types, and fixup existing usage.
• Move fetching and most processing logic to backend, and set up tRPC routers and procedures.
  • Notably, we now rely only on the API cache layer for WebSoc, since we don't do anything fancy with it and a 5 minute TTL is probably reasonable. Because the backend now makes the requests, everyone fetching the same endpoint with the same params will hit cache, and as a result we can "invalidate" the cache by passing in a new dummy param.
  • Still caching grades on the frontend though since there's some Interesting logic there.
• Move away from GraphQL and nuke dead code.

Test Plan

Tested locally, server related things need staging for tests.

Also someone else should run through their normal routine and verify that everything still works as expected.

Things That Still Need Doing

• Migrate fuzzy search.
• Once feat: properly type prerequisite tree anteater-api#30 gets merged we can remove the local declarations for the prerequisite tree.

Future Follow-Up

• Replace Arktype with bare TS types and Zod where validation is actually necessary, since all our other projects are using Zod. (Sorry Brian.)
• There's a bug where the API tries to return enrollment history data objects for courses we don't have enrollment data for. This needs to be resolved on the API end but for now I've added a shim in the tRPC router.
  • Now tracking this in Resolve empty enrollment history entries anteater-api#31.
• Remove lint-staged config from backend #1030
• feat: Implement Calendar and Term Endpoints #802 take 2

[MinhxNguyen7]

The backend deployment doesn't work. I should've checked that first

[MinhxNguyen7]

Some searches aren't working:
"ICSH32"/"ICS H32" return nothing.
"MAE93" returns nothing, even though it works right now.
"ICS139W" seems to work with fuzzy, but then no results show up

[MinhxNguyen7]

Should replace these messages about PeterPortal API with Anteater API

[MinhxNguyen7]

The finals part of the tour isn't working. I think it's because you changed the sample data factory

[MinhxNguyen7]

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           )____)____)_____)\\
         _____|____|____|____\\\__
---------\                   /---------
  ^^^^^ ^^^^^^^^^^^^^^^^^^^^^
    ^^^^      ^^^^     ^^^    ^^
         ^^^^      ^^^