Only show lockfile warning on lazy activation

[vinistock]

Motivation

There are two types of workspace activation: eager or lazy.

Eager happens when we activate the extension. We check to see if there's a lockfile in the workspace root and then proceed to activate. Lazy happens when a Ruby document is opened in a workspace we had not activated before.

Currently, we're showing the lockfile warning on both, which is a poor experience. We should really only show it on lazy activations, giving the chance to the user to do something about it.

But if the workspace is not a Ruby workspace, then we shouldn't show it and should just default to not starting the LSP.

Implementation

This PR makes a few tweaks to the experience:

• We now differentiate between an eager or a lazy activation
  • On eager activations, we do nothing if there's no lockfile (for the scenario of workspaces that may be purely written in another language)
  • On lazy activations, we still launch the language server, but we display a warning to the user prompting them to either look at the documentation or ignore that warning

[parsley42]

This looks great to me and will definitely fix the UX.

[vinistock]

Thanks @parsley42! I appreciate the feedback 🙏.