Add focus mirrors to I19

[noemifrisina]

Instantiate the focus mirror devices in the i19-optics definition. It should be possible to re-use the already existing device, to which the piezo actuators should be added as they want to be able to set voltages to them to fine steer the beam.
Create an access controlled device that can be instantiated for I19-1 and I19-2.

(See also I19-885 - UI side in GDA wip)

Acceptance Criteria

• There is a focus mirror device with piezos
• There is an access controlled device for the mirrors instatiated in the two hutches