codeintel: Simplify GraphQL resolvers
Created by: efritz
Inline the lsifserver/client logic directly into the graphql resolvers.
This results in a bit of a sloppy package, which I intend to clean up and test aggressively in a later pass during this milestone. Integration tests pass with the inlining, so there should be no regression in behavior.
Suggested reading order:
- enterprise/internal/codeintel/resolvers/resolver.go
- enterprise/internal/codeintel/resolvers/query.go
- enterprise/internal/codeintel/resolvers/upload.go (only new, do not look at diff)
- enterprise/internal/codeintel/resolvers/upload_connection.go
Everything else is deleted or is a small util/conversion file.