[#24] Improve 'Remove Branch' button workflow

[d-gs]

Type of request

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Refactoring
• [x] Documentation or documentation changes

Related Issue(s)

Closes #24

Concept

Description of the change

• Enable the Remove Branch launcher even if the branch is already checked-out
• In case of the branch already checked-out, switch beforehand to the internal GEM branch

Description of current state

Currently the remove branch launcher is disabled if we are already on the feature branch. This means that before deleting a branch, you should manually checkout a different branch and then do the deletion.

Description of target state

On the command to delete the branch, the checkout happens if it is already checked out. Of course, it should still fail if the worktree is not clean.

Checklist:

• [x] All the commits are signed.
• [x] My code follows the code style of this project.
• [x] I agree with die CLA.
• [x] I have read the CONTRIBUTING docs.
• [x] I have added/updated necessary documentation (if appropriate).

[d-gs]

@davu-all - back to you with the requested changes!