Bluetooth: CSIS: Refactor bt_csis_client_discover_sets to use member

Refactor bt_csis_client_discover_sets to use the
bt_csis_client_set_member struct instead of a bt_conn.
The bt_csis_client_set_member represents a remote server
(set member), and make it possible to avoid sending indexes
of instances around instead of bt_csis.

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