[mlir][Linalg] Combine canonicalizers that deal with removing dead/redundant args.

`linalg.generic` ops have canonicalizers that either remove arguments
not used in the payload, or redundant arguments. Combine these and
enhance the canonicalization to also remove results that have no use.
This is effectively dead code elimination for Linalg ops.

Differential Revision: https://reviews.llvm.org/D123632