Bluetooth: Audio: Rename remaning MICS files to MICP roles

Rename mics => micp_mic_dev (MICP Microphone Device)
Rename mics_client -> micp_mic_ctlr (MICP Microphone Controller)

This does not change any lines in the code.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>