[MLIR][Bufferization] Introduce `EmptyTensorToAllocTensorOp`

[MLIR][Bufferization] Introduce `EmptyTensorToAllocTensorOp`

Introduce a new transform operation to replace `tensor.empty` with
`alloc_tensor` operations. The operation is a pass-through if the target
operation is already a `alloc_tensor`; otherwise, it expects a
`tensor.empty` as a target. Currently, it does not return any results.

The operation is expected to run before `one_shot_bufferize` as
`one_shot_bufferize` rejects `tensor.empty`.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D140026