include a src parameter for write operations (eg., in turn_on_platform_port); also introduce new operation set_over_current(platform_id, port_id, ma, us, src). This also as part of the recent CI-OMS interface changes.
update capabilities test with new set_over_current operation
as decided in context of mission execution, turn_on/off_port again requires port_id always (not via instrument_id-based mapping)