[mlir][Bufferization] Add support for controlled bufferization of alloc_tensor (#70957)

This revision adds support to
`transform.structured.bufferize_to_allocation` to bufferize
`bufferization.alloc_tensor()` ops.
    
This is useful as a means path to control the bufferization of
`tensor.empty` ops that have bene previously
`bufferization.empty_tensor_to_alloc_tensor`'ed.