I just pushed the chain of gerrits  that introduces:
1) language protocol extensions (contributable via OSGi components)
2) language server configurations (contributable via OSGi components)
that allowed to
3) extract server-specific parts to the dedicated bundles
All the new types has "internal" status and may require additional work
before being promoted to the API.
Also there is a Gerrit prepared  to remove cquery support from the
@Jonah please provide your vote.