Global: Rework services, scripts and deployment

• Services: Add a new psql container that takes care of dumping the db data on specified intervals
• Migration scripts: Change interpreter to sh, add the possibility to specify input/output migration file name, change docker command to docker compose
• Realms: Remove file from source control
• CI: Rework scripts
• Closes #2 (closed), #4 (closed)

requested review from @maximilian.moser

assigned to @sotirios.tsepelakis

Imo there's one thing worth mentioning here: The repo was previously transferred directly from the runner and the git config was kind of outdated and problematic (fetching from the origin was failing; a single quote was somehow appended to the remote URL causing fails). I freshly reinitialized the repo and added a new token for the pull operation.

merged