Optimistic persist

[erano067]

Hi,
I was thinking of adding an optimistic feature to the persist middleware, in general, what I wish for is that for any async persist the middleware will clone the current state into oldState, change the UI, and then make the appropriate call to the async storage(backend/indexedDb, etc..) with a .catch(error=>...) that does a rollback to the by set(oldState)

In the options we can add an onError callback that will be called when reverting back, so users can pop a toast/log it, etc..

What you guys think?