Open multi-diff editor when opening a new worktree from a PR

[eamodio]

When we complete the flow of creating a worktree from a PR, we should open the changes in the PR in the multi-diff editor.

If the GH PR extension is installed, we should try to either get it to open the multi-diff editor, or figure out the uri schemes they are using so that commenting will work in that editor.

[d13]

So let's split this into two separate deliverables:

• Using the completion of the deeplink to open a workspace, open the multi-diff using our normal functionality openAllChanges
• GH PR extension detection

[sergeibbb]

@nzaytsev @axosoft-ramint

I cannot verify :-(

open-pr-diff-in-worktree.mp4

[axosoft-ramint]

@sergeibbb A new requirement emerged over the course of developing this that was not reflected/updated into the issue description above:

The PR diff will only show if a worktree was created during the "Open in Worktree" flow. If an existing worktree was found and opened, the PR diff will not show.

So if you opened an existing worktree in the above example, this is intended behavior. Not sure if that is the case in your test above or not.

[sergeibbb]

Thank you @axosoft-ramint!

Confirmed:
https://github.com/user-attachments/assets/b0264ecf-b784-4592-b89e-d3c3c38c0301