feat: store user ui preferences

[acellard]

Description

This PR is a result of October 27th "flash hackathon" involving @Milouu and @acellard. The goal was to figure out how to properly manage user ui preferences in the backend, and provide api to get, retrieve and update them. For now, such preferences involve columns display list and favorites compute plans. With likely more preferences in the future. To keep it flexible and leave the responsibility to the frontend, the preferences are stored in a json field.

This PR also does some refactoring to use serializer to validate data.