Add new script Compare_Ome_Xml.py

[will-moore]

Compare OME.xml between images of the same name in selected Dataset(s).

Script added under "Export_Scripts".
Message gives info on how many images are compared and any differences.

NB: If you've imported images from NGFF, you'll need to manually rename them to match images imported from original files.

cc @pwalczysko

[sbesson]

See ome/ZarrReader#31 (comment) for a potential concern about the diffing of the trees

[will-moore]

9213cfe compares Planes only with other planes of the same Z/C/T index.
This doesn't check that there are the same number of Plane elements in both XML docs - It simply stores the Plane in a dict with Z/C/T key, and if there's a Plane already stored with that key then we compare them (assumes they are from the 2 different XML docs, but doesn't check that).

For multi-T image (that was previously flagged as non-matching XML) this now passes: https://merge-ci.openmicroscopy.org/web/webclient/?show=image-231218
For multi Z/C/T image, this still fails https://merge-ci.openmicroscopy.org/web/webclient/?show=image-230717
with output like:

Comparing planes Plane:1:1:14
-------- ** difference... ** --------------
nodeA {'DeltaT': '3656.5830078125', 'DeltaTUnit': 's', 'ExposureTime': '0.05000000074505806', 'ExposureTimeUnit': 's', 'PositionX': '925.13', 'PositionXUnit': 'reference frame', 'PositionY': '-5910.84', 'PositionYUnit': 'reference frame', 'PositionZ': '-0.499', 'PositionZUnit': 'reference frame', 'TheC': '1', 'TheT': '14', 'TheZ': '1'}
nodeB {'DeltaT': '1766.001953125', 'DeltaTUnit': 's', 'ExposureTime': '0.07999999821186066', 'ExposureTimeUnit': 's', 'PositionX': '925.13', 'PositionXUnit': 'reference frame', 'PositionY': '-5910.84', 'PositionYUnit': 'reference frame', 'PositionZ': '-0.499', 'PositionZUnit': 'reference frame', 'TheC': '1', 'TheT': '14', 'TheZ': '1'}
...----------------------

[will-moore]

This has served it's purpose - closing until we need it again...