Slightly better project loading error messages

[TheAngryByrd]

• Centralizes and logs Cancellation of LSP endpoints as Info messages
• Converts some types from Options to Results for better errors
• Changed messages to inform the user the projects might not be loaded (yes we still need to fix the auto restore but that's a more work)
• Refactored the selectProject to be an interface rather than a FSharpFunc. Makes it easier to swap later. Adaptive requires comparisons and FSharpFuncs aren't comparable.

[baronfel]

This should reduce a lot of noise :) Thanks @TheAngryByrd!