[12.x] Fix model serialization in queue jobs

[axlon]

PR #58482 introduced morph map support for model identifiers, this PR addresses 2 bugs introduced by that PR.

1. Deserialization always uses the morph map, even when not enabled. If a class happens to be registered as a morph alias, jobs using that model will be unable tk unserialize, e.g.:

       Relation::enforceMorphMap([
           'user' => User::class,
           'App\\Models\\User' => SomeOtherUser::class,
       ]);

2. The above bug can be avoided by enabling morph maps (so opting in to the new feature), because then the model identifier will always use the morph map making serialization and deserialization be in sync again. However, you then run into the second issue; which is that collection deserialization was not updated to support morph maps and will then break

Edit: small note; ModelIdentifier::$class should probably be made protected/private on 13.x, consumers should not be using it directly and should instead be calling ModelIdentifier::getClass()