Various deployment improvements

Bucket to track various deployment improvements

- [x] Staging and prod environment need to allow deployment from devel branch. This is probably, because the `repository_dispatch` event is running on devel. Maybe we manage to reach a simpler setup without the need for `ci-passed` events. See screenshot below for the error message.
- [x] Move CI tests, image build & deployment into a reusable workflow. This probably makes it possible to avoid repository_dispatch ci-passed events as we can write specific composite workflows for specific branches using reusable workflows.

- [x] Docker images are built and overridden each time, the deployment runs, even if the same SHA has already been built. We could check for existence of the SHA image and skip the built step if it already exists.

- [ ] Replace FAST_FORWARD_TOKEN from Bacluc to ecamp core

- [ ] Deploy via Tag