Bluetooth: Audio: Rename bt_vcs to bt_vcs_included

Rename the struct from bt_vcs to bt_vcs_included, and
rename bt_vcs_get to bt_vcs_included_get as that is more
descriptive of the value returned.

Furthermore, this will also allow us to use bt_vcs as
an opaque pointer to a VCS service instance (local
or remote) to match the service instance pointers of
AICS and VOCS.

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