[TOPI] Use integer arithmetic for topi.image.resize

Prior to this commit, floating point expressions were used to map
between different-sized pixel arrays.  These floating point
expressions are less aggressively optimized by `RewriteSimplifier`,
which can prevent some optimizations

This was first noticed during investigation into issue #13508.
Benchmarks of `topi.image.resize` showed 1000x and 50x performance
improvements using the LLVM and CUDA backends, respectively, by using
integer expressions instead of floating point.  This performance
improvement is partly driven by enabling
`tir.transform.VectorizeLoops` to recognize vectorizable indices,
where the round-trip through floating point previously prevented that
optimization.

Author: Lunderberg