bluetooth: tester: refactor CSIP btp command

Refactor CSIP btp commands by removing the 'count' parameter from
set_coordinator_lock and set_coordinator_release functions.
If we want to support lock/release procedure on subset of set members
in the future, 'count' param doesn't indicate a specific set member.
Instead, introduce 'address_count' and 'addr' array params, although their
usage is not yet implemented.

Signed-off-by: Piotr Narajowski <piotr.narajowski@codecoup.pl>