LeAudio: Allow for vendor codec specific capabilities

Support propertiary codec specific parameters in PAC records.

Bug: 308427707
Test: atest --host bluetooth_le_audio_test bluetooth_le_audio_client_test bluetooth_test_broadcaster bluetooth_test_broadcaster_state_machine bluetooth_le_audio_codec_manager_test
Flag: EXEMPT; refactor for the multicodec support, verified with unit tests
Change-Id: Ie2b9d1a8258a7c84efc77ee847366d9010dc98fc