[V2][Sessions] Cleanup regularly expired sessions

[LoicPoullain]

Issue

When a session is expired in a TypeORMStore or MongoDBStore, it is destroyed only if the app tries to read it or if Store.cleanupExpiredSessions is called.

This means that users should run periodically the cleanupExpiredSessions method (like in Django).

This is not very handy. The framework should take care of this without multiplying by two the number of requests to the database.

Solution

Like in Laravel, cleanup the expired sessions regularly when a session is committed based on a random number between 0 and 50 (can be modified in the config)

[LoicPoullain]

Resolved in v2