Check that read happend before save.

[lavrukov]

In our service, we predominantly do not use blind writes. We encountered a bug in the user code where we read an object in one transaction and saved it in another without a preliminary read. As a result, we ended up with an incorrect value in the database.

It's difficult to protect against such issues, however, an optional check can be added in the InMemoryRepository before saving: if the object is present in the database, we check the cache, and if the required object is not there, we fail. There are several problems here:

• In our current implementation, we often use readAll(), so we cannot rely solely on the storage output.
• Relying on the standard cache is not feasible, as it does not always contain all read objects. A custom cache is needed.
• We need to consider how to add exceptions for cases where blind writing is justified. For example, adding a wrapper similar to the one in FullScanDetector.