Migrate the AesCtrHmacAeadKeyManager to a KeyTypeManager.

The tests will be migrated in a follow up cl.

*NOTE* that I change how some of the things are done. In particular, previously:
  * The underlying HMac was generated by calling the registry.
  * The underlying HMac key was manually created, without going through the registry. The version was set wrongly (to the version of the AesCtrHmacAeadKeyManager instead of the HMacKeyManager).
  * The underlying HMac key was now validated in this key manager.
  * The underlying HMac format was not validated.

After this cl, I use the HMac KeyTypeManager to validate things; and I do that directly without going through the registry.

I think the proper way would be to have some kind of registry access, where this KeyManager can obtain the new HMacKey *Type* manager, and then do the proper things. But this is complicated :/ I think this here is the second best solution.

PiperOrigin-RevId: 264568255