Support Bitbucket as a repository type in project settings

Following up on #3780, please add Bitbucket support as repository type for commit and source files links.

For now I'm using and interested in Bitbucket support. I'm not sure if adding a few more hosting platforms from the most used ones would also be relevant. I'm thinking SourceForge and Codeberg from the top of my head, but maintaining a whole list is probably not wanted on your side.