✅ Move creation test faking out of test::create and into specific tests

This moves the faking of the quiddity creation test out of the general quiddity::test::create function and into the specific tests that need faking.

This allows us to intentionally introduce faking only at places that needs it and to have tests that can meaningfully test quiddity creation when it really matters.

This introduces more specific faking in the check_v4l2_plugin test, in the check_pulse_src test and in the check_test_full for the v4l2, nvenc, ltcsource and ltcsink quiddities so that our pipelines still pass for now.

Issues related to these faked tests were created so that we can have a discussion about what the way forward should be : #161 #162 #164 #165