Add warning on CKM TrustZone space leak

Add warning on CKM TrustZone space leak

Current implementation of ckmc_remove_user_data is not able to remove
individual objects from TrustZone, because their names are stored in a
possibly encrypted database. This rarely happens in actual code, but
tests extensively use this function to clean up objects they create.
Because of this, running CKM tests multiple times with TrustZone enabled
may exceed TrustZone limits.

Fixing the behaviour is a larger task, and making all tests clean up
individual objects is too verbose, complex and error-prone for a bug
workaround that only affects developers (this approach has already been
tried once, and it was removed years ago).

I have added a heuristic check that tries to create a single-byte data
object in TrustZone. If that fails, it displays a warning message
explaining the problem and suggesting to reset TrustZone and key-manager
state, as well as instructions on how to do use using Tizen emulator and
tef-simulator.

Change-Id: Id99c22c33f3e5adfbeff5c7b1b58d2d995ed4cca