Freeze value in MemoryCache
Following the discussion on #9557 (closed), I'm wondering if we should not freeze the value stored in the Memory cache.
I guess we will need a different freeze method which can be based on:
types.MappingProxyType for dict
frozenset for set
tuple for list
I think it will not be too costly if we make the conversion only on set and not "unconvert" on get.