LeAudio/CodecManager: Add configuration requirements

Wrap the existing requirements into a single struct to avoid changing
the CodecManager interface when we add the aditional requirements.
This also simplifies the mocking.

Bug: 308428860
Flag: EXEMPT; mechanical refactor, no functional changes
Change-Id: I7f3f09354dc2aab75ac09f20e7a117aea69ac65e
Test: atest bluetooth_le_audio_test bluetooth_le_audio_client_test  bluetooth_test_broadcaster bluetooth_test_broadcaster_state_machine bluetooth_le_audio_codec_manager_test