Config versioning
- added DynamicSupervisor, which starts Pleroma deps and restarts config dependent deps
- added versioning for in database config. A new version is created from changes that are passed to the config update/delete endpoint. Every version contains a backup with all changes added through an update. Versioning supports rollbacks with N steps. With a rollback, all versions that come after the version on which the rollback was made are deleted.