chore: Replace isIntGreaterThan with inline function

isIntGreaterThan was never used other than as a zero comparison, this was far more complicated and unit-tested than was worthwhile

I didn't bother with the Number.isInteger check, as that only catches floats and true. true is treated the same as 1, so will work fine. Floats might be weird (i.e if perPage == 1.5) but I don't think a validator is the place to deal with that