Merge persistent_sessions and persistent_state #3425
Description
Is your feature request related to a problem? Please describe.
I'm always frustrated when SN configuration has too many things to care about.
Describe the solution you'd like
Move persistent_sessions data to persistent_state, use single DB for local state. Session persistence should be controlled via a flag.
Keep compatibility, migrate existing DBs, config is to be deleted in subsequent versions.
Describe alternatives you've considered
Use a DB per data type, it sucks.