Reconcile I23 goniometer with Aithre goniometer

[JamesDoingStuff]

Code should be reused between the goniometer on the I23 beamline and the goniometer in the Aithre laser shaping setup - especially for the OAV-plane signals proposed in #1164 and #1215.

The I23 goniometer is constructed as as XYZPositioner upon which omega, kappa and phi are added (and now these signals). The Aithre goniometer, on the other hand, does not have a sample X stage, nor kappa and phi rotation axes. It does, however, have additional X Y and Z translation axes that the goniometer sits on. These PVs clash in naming convention with those of the I23 goniometer. For a summary of PVs of the two:

PV in I23 Goniometer	Equivalent PV in Aithre Goniometer
X	-
Y	SAMPY
Z	SAMPZ
OMEGA	OMEGA
KAPPA	-
PHI	-
-	X
-	Y
-	Z

Acceptance Criteria

• Duplicated code is minimised for the two goniometers
• Each connects and tests pass as expected