feat: Include `idiff` in python wheels

[nvmkuruc]

Is your feature request related to a problem? Please describe.
OpenUSD uses idiff as its imaging diffing tool in regression tests, requiring a build of OpenImageIO even when not building the OpenImageIO plugin.

Describe the solution you'd like
Provide a prebuilt idiff via python wheel as an alternative to building OpenImageIO.

Describe alternatives you've considered
OpenUSD could switch to using oiiotool as suggested here: PixarAnimationStudios/OpenUSD#3897