CLaSP: Respond to User study feedback

[ryanbrandenburg]

CLaSP had it's first implementor who isn't me, so we got real-world feedback! Mostly it was positive but below is the take-aways I noted. IMO these mostly fit into things we can implement in the future to make people's life easier and a need for more/better documentation. Noting it here so I can split things up into sub-issues where appropriate.

• More guidance on what belongs where (maybe methodHandlers have their own service constructor ETC
• Lack of clarity on purpose of LifeCycleManager and what it can do for you
• Better comments for ConstructLspServices
• InitializeManager as part of InitializeHandler?
• Built in Noop/DefaultLogger?
• Purpose of RequestCOntext and RequestCOntextHandler is unclear (Doc Comments)
• DefaultDocumentManager may be helpful
• Double check doc comments on MutatesSolutionState
• Sending requests back to client left to own devices (Include on LanguageServer?)

[ryanbrandenburg]

Items 2, 3, 6, and 8 are (hopefully) resolved by https://github.com/dotnet/roslyn/pull/64446.