Set the transmission implementing the acess control architecture

[noemifrisina]

Write plans that directly control the attenuator on I19 and set the transmission to the requested value. These plans should be in the optics folder and implement the same architecture as the shutter control, using the check_access decorator:

@check_access
def set_transmission():
    ...
     yield from bps.abs_set()

Acceptance Criteria

• There's plans that can set the transmission and are decorated in the optics module