Allow Multiple Diffing Algorithms

[NWPlayer123]

As discussed on Discord, having the option to switch between diffing algorithms is occasionally useful when using objdiff to decompile a function, even if Patience is a good default.

Ideally this would be some minimally-intrusive system like a trait with a compare() function that can be plug-and-play so we can use different ones for e.g. hex view vs assembly view. It might also see more use if it's re-added as a dropdown at the top of the diff column for easy switching, instead of being behind several clicks in the menu.