[mlir][ArmSME] Lower multi-tile stores to a single loop (#96187)

This adds a new pattern that can legalize a multi-tile transfer_write as
a single store loop. This is done as part of type decomposition as at
this level we know each tile write is disjoint, but that information is
lost after decomposition (without analysis to reconstruct it).

Example (pseudo-MLIR):

```
vector.transfer_write %vector, %dest[%y, %x], %mask
  : vector<[16]x[8]xi16>, memref<?x?xi16>
```
Is rewritten to:
```
scf.for %slice_idx = %c0 to %c8_vscale step %c1 {
  %upper_slice_mask = vector.extract %mask[%slice_idx] ─┐
    : vector<[8]xi1> from vector<[16]x[8]xi1>           |
  %upper_slice = vector.extract %upper_tile[%slice_idx] |- Store upper tile
    : vector<[8]xi16> from vector<[8]x[8]xi16>          |
  vector.transfer_write %upper_slice,                   |
    %dest[%slice_idx + %y, %x], %upper_slice_mask       |
    : vector<[8]xi16>, memref<?x?xi16>                  ┘
  %lower_slice_idx = %slice_idx + %c8_vscale                 ─┐
  %lower_slice_mask = vector.extract %mask[%lower_slice_idx]  |
    : vector<[8]xi1> from vector<[16]x[8]xi1>                 |
  %lower_slice = vector.extract %lower_tile[%slice_idx]       |- Store lower
    : vector<[8]xi16> from vector<[8]x[8]xi16>                |  tile
  vector.transfer_write %lower_slice,                         |
    %dest[%lower_slice_idx + %y, %x], %lower_slice_mask       |
    : vector<[8]xi16>, memref<?x?xi16>                        ┘
}
```