Merge branch '421920-update-policy-editor-to-add-actions' into 'master'

Add button to add action if one does not exist

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/134177



Merged-by: Lukas 'Eipi' Eipert <leipert@gitlab.com>
Approved-by: Sharmad Nachnolkar <snachnolkar@gitlab.com>
Approved-by: Lukas 'Eipi' Eipert <leipert@gitlab.com>
Co-authored-by: Alexander Turinske <aturinske@gitlab.com>