Remove default persistence strategy and replace by suggested strategy

[mherwege]

See discussion here: openhab/openhab-addons#16496 (comment)

It would make sense not to have a default persistence strategy for a persistence service anymore, which automatically kicks in even if no items are defined. It could be replaced by a suggested strategy that is proposed when installing the service, but does not kick in automatically without confirming or changing the configuration.

As this would have been a major (and breaking) change, the linked PR was accepted. But this could be something to revisit for OH 5.0.