skimage regionprops depreciating xy coordinates

[ahijevyc]

Eventually we need to accept the objects' region properties in row-column coordinates, as opposed to xy.

skimage.measure regionprops function will stop using xy coordinates and use row-column instead.
STObject.py uses it for shape properties.

We could specify regionprops(..., coordinates='xy') for now to avoid the warning, but this will break.

See https://scikit-image.org/docs/0.14.x/release_notes_and_installation.html#deprecations for details on how to avoid this message.
warn(XY_TO_RC_DEPRECATION_MESSAGE)