Remove assertions in slicing method

[NickEntin]

There are some valid use cases where you want to be able to slice more than the available width/height, such as when your content has a minimum size and your sizing rules allow for content to extend beyond the bounds if you view is sized beneath its ideal size.

We should instead have a dedicated non-asserting alert method for which consumers can create a symbolic breakpoint to detect, following the pattern of ParalayoutAlertForMismatchedAlignmentPositionTypes and ParalayoutAlertForInvalidViewHierarchy.