Create feature branch for 1.4.5

All tickets in 1.4.5 will be based of this feature branch (previously it was main). So now main will be the defacto release branch.

Motivation of this this change is to make code management easier (i.e. I can release a hot patch to public releases without affecting new work). GitLab does not support feature branches so I am going to do this manually. What can go wrong here?