Evaluate Persisten Catalog Data storage

Since the Data Catalogue api-server will likely not store any persistent data by itself (to make updates via CI/CD easier), some kind of persistent storage is required.

Any kind of database is likely a bit too much for the expected amount of data, so a possible alternative might be simple json files in a docker volume, that might be dynamically attached to the docker image containing the API server. This volume would then be attached to the docker image containing the api-server, and json files are simple enough, that even a full rebuild of the api-server would have access to the data without any big problems.

One the other hand, this entire project is something of a small playground to test things/ train for the Data Logistics service, so deliberately overengineering a bit as also a valid strategy.