Tokens Prune

[andreareginato]

With the actual system tokes grow up really fast. We need a way to control the number of created tokens. We can build a worker or we can set a check during the token creation, going to delete the tokens older than (for example) one week. Before doing so we need to check really well how tokens are used in all parts of Lelylan (webhooks, realtime) and what happens when I delete one of them.