In some respects this is a temporary thing until we get proper options support in cohosting, but in other respects having the service just take the one option value it actually needs is much nicer

# Conflicts:
#	eng/Versions.props

This still leaves in place the text sync endpoints, and updates to the LSP servers
project system, so that everything else functions as expected

This also nicely lets us Find All Refs on the Cohost feature flag and see all of the code that can be deleted :)

Brings semantic tokens to cohosting, so there is an easy visual
indicator if things are working.

Right now colours are disco on first open of a file, but are fixed with
an edit. This is actually a good thing, as it will help me diagnose and
improve the document system in cohosting.

)

If nothing else, this cleans up the logs when trying to work out why
your cohost endpoint isn't working :)

Merged the PR from the couch thinking I'd actioned this feedback. Turned
out I'd made the changes on my other machine but hadn't committed 🤦‍♂️

…side of the world (#9766)

In theory this means the end of document sync issues forever!

In practice there is one fire-and-forget async method call here, from a
sync context, so edge cases will still creep in. But all of this code
should be deleted eventually anyway :D

PR feedback from a merged PR