Bluetooth: OTC: Use OTS defines and types instead of separate ones

Update the Object Transfer Client to use OTS defines and types instead
of the ones left over from the previous "le-audio local" object
transfer service:
DIR_LIST, object ID size, OACP and OLCP

Remove the no longer used defines and types from the OTC header file.
Exception: The OLCP sort order defines have not been removed, but
moved to the olcp internal header file, for expected later use.

Signed-off-by: Asbjørn Sæbø <asbjorn.sabo@nordicsemi.no>