Split up test_cluster_handler_registry test

[TheJulianJES]

Initially, the test_cluster_handlers.py:test_cluster_handler_registry test didn't do a whole lot.
With home-assistant/core@37707ed#diff-7126848f7becb03b017f77521684b3372d7a95f1859f6e9763493af52de8a780, it was expanded with quirk IDs and also checks a lot more now, including making sure the test can find all custom clusters defined in zha-quirks if they're used in a cluster handler in ZHA. This is done by looping over the (v1) quirks device registry and looking at the signature/replacement of all quirks.

We might want to split up that test in a quirk id related test and one that verifies the clusters used for cluster handlers are defined somewhere.

Related PRs:

• Fix quirk ID test ignoring custom clusters in v2 quirks #264
• Match ZHA Custom ClusterHandler on a Custom Cluster using a unique id for the quirk home-assistant/core#101709