[mlir][linalg] Include InitTensorOp in tiling canonicalization

Tiling can create dim ops and those dim ops can take `InitTensorOp`
as input. Including it in the tiling canonicalization patterns
allows us to fold those dim ops away.

Also sorted the existing ops along the way.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D110876