In the UI, expose the account used for authenticating to Bitbucker Server-type repositories and provide a button to test the connection

When a Bitbucket Server-type linked repository in created in Bamboo, authentication is handled by using the credentials of the user who created the linked repository. This is great because it simplifies the authentication process, but also causes the repository to break if the user ever leaves the company or loses access to the repository in Bitbucket Server, then the repository breaks for everyone on Bamboo's side. Fixing this is easy - just re-save the repository (thus using your credentials for authentication). However, diagnosing this problem can be tricky, especially if you aren't aware of how authentication is handled in the first place.

To help fix authentication issues when they arise, two things would be good:

1. Display who's credentials are being used whenever a repository is mentioned in Bamboo (i.e. Linked Repositories, Plan Configuration, Branch Configuration)
2. Add a button that tests these credentials.