Extend QuantifyMIF to also support brightfield images

[jacob-rosenthal]

Right now QuantifyMIF is used for taking a cell segmentation mask and computing cell-level statistics into a counts matrix. However, there is no reason why this should be limited to IF images. We may also want to look at cell features in H&E images - channel intensities may not be as meaningful but the other properties computed by regionprops should be useful.

Maybe we can move the existing functionality into a new Transform called something like QuantifyCells, and then keep backwards compatibility by having QuantifyMIF call QuantifyCells internally plus maybe give a deprecation warning