Remove gitlab integration

This is a followup of initial gitlab support removal in backend code.

This issue covers the removal of:

All oauth client support in profile:
- adding an account
- (re) connecting an account
- deleting an account
- listing all accounts along with their states
Add a repository view
- and its button from the list of repos

A user should still be able to list and view details of a repo, but not create a new one