Implement upstream changes from scikit-image 0.23 (part 2 of 2: morphology)

[grlee77]

There were a number of non-trivial changes to the morphology module, so I broke those out from the other changes in #727. Please review and merge that MR first before reviewing this one.

Highlights from upstream are:

• binary morphology functions have a new mode argument that controls how values outside the image boundaries are interpreted
• grayscale morphology functions have new mode and cval arguments that control how boundaries are extended (these were already available in scipy.ndimage/cupyx.scipy.ndimage, they just weren't exposed via the skimage/cuCIM APIs)
• binary and grayscale morphology functions have bug fixes in the case of even-sized/non-symmetric footprints
  • additional corresponding test cases were added

Aside from the upstream changes, novel changes in this MR are:

• refactored utility functions to mirror and pad the footprints to allow use with the cuCIM-specific optimization of passing a tuple for rectangular footprints instead of explicitly allocating a GPU footprint array
• refactored some test cases to better use pytest.mark.parametrize
• some grayscale tests now compare directly to skimage CPU outputs instead fetching previously saved values
• bumped our version pinning for scikit-image to allow 0.23.x to be installed

I marked as "non-breaking" as the existing behavior has not changed except in the case of the bug fixes for even-sized footprints.