Can't create an entity after all its fields decryption and module removal

I tried to remove some field_storage_definitions related to the field_encrypt module in the key_value table (during module uninstallation). After that, I was able to create new users.
I created a Merge request with my changes.

Here's the patch if someone needs it.

@rsych thanks for your patch, it works fine for me, however, it seems to me that we can provide some code changes.

It's been 2 weeks with no response, so I think I can contribute. Needs to be reviewed now.

Looks much better now. Thanks @taraskorpach!
I don't see any other problems problems.

Leaving at RTBC.

Updating the target to 3.2.x as that is now the active dev branch. It is important to fix this but we need a test to confirm the behavior.

I created a new MR for 3.2.x and tried to add a test.

However, I'm having trouble replicating the behavior described in the issue in the test; the test passes even without the change to the uninstall function, so the test does not currently work.

Also, 🐛 After Setting the Fields to encrypt the Form Breaks Active needs to get in or $this->setFieldStorageSettings(FALSE) will crash.