Two level cache service

[RostislavKreisinger]

Describe the expected outcome of your requested feature

I would like a tool in the framework that serves as a replacement for a manually written local cache. A problem with manual programming of the local cache in the service is the frequent omission of emptying when clear is called on the entityManager. If entities are saved in the local cache, then they lose their reference after deleting the entity manager. An example is the local cache of currentCustomerUser and its associated subscriber on the onClear event.

A possible solution would be TwoLevelCacheService with invalidation resolved on onClearEvent.

If its use in the code would be sufficiently known and widespread, then in the future it can speed up the framework itself and prevent invalidation problems.