Fix GitLab settings page crashing before setup

Opening Settings > GitLab in a workspace that had not connected a GitLab group yet showed "Something went wrong" instead of the connect button, so the integration could not be set up from the dashboard.

• Fixed the GitLab and Bitbucket settings pages so they load correctly before an integration is connected
• Added error reporting from the dashboard's error screens, so crashes like this one are detected by the team instead of relying on user reports