fix: retry loading failed project
When the extension fails to load GitLab project for the repository, it doesn't provide any additional information.
This MR introduces a diagnostics command that the user can trigger by clicking on a failed project item.
This way we'll provide users with more information and in some cases (when there are multiple remotes) even a way to recover.
On the video you see:
- When the extension fails to load the project again, it shows the output log
- When it succeeds, it reloads the tree view with projects
Related to #492 (closed)