Refactor meta package to allow updates of key and make keys unique
This is an unfortunate MR, as it touches two different concerns:
- refactorings in the meta package to enable settings to be updated
- and quite entangled to such change, changes the way we store the http session keys to use json instead of the deprecated interface (from before the refactoring above mentioned).
NOTE to myself: try to work on smaller pieces in the future.
Edited by Leandro Santiago