Overview

@pchiusano mentioned that it would be nice to a quick way to open a given definition on Share.

This adds the Unison API which allows us to add a VS Code context menu option to do exactly that;

VS Code PR here.
This PR (the unison one) must be merged first.

Implementation approach and notes

• VS Code sends the LSP a request, including the file URI and location of the cursor
• We resolve that file location to the relevant symbol (note that if the file isn't parsing this may not succeed)
• We look up the remote mapping for the current project/branch.
• We build a link against that remote project & branch using the FQN of the relevant symbol.
• Note that if the remote and local states differ, that FQN may not exist on Share, at which point Share just shows a "couldn't find it" message.

Test coverage

• Manual testing