[mlir][tensor] Adapt FoldTensorCastProducerOp pattern on DPS interface.

This revision adapts the pattern in LinAlg to work on DPS interface, and
adds it to canonicalization patterns of tensor dialect. The
InsertSliceOp is skipped in the pattern because it has its own logic
about folding tensor.cast ops.

Reviewed By: pifon2a

Differential Revision: https://reviews.llvm.org/D139375