[mlir][vector] Refactor vector-transfer-to-vector-load-store.mlir (NFC) (#105509)

Overview of changes:

- All memref input arguments are re-named to %mem.
- All vector input arguments are re-named to %vec.
- All index input arguments are re-named to %idx.
- All tensor input arguments are re-named to %src/%dst.
- LIT variables were updated to be consistent with input arguments.
- Renamed all output arguments as %res.
- Removed unused argument in `transfer_write_broadcast_unit_dim`.
- Unified identation of `FileCheck` commands.
- Split `transfer_write_permutations` and  `transfer_write_broadcast_unit_dim` into tensor and memref variants.
- Renamed `transfer_write_permutations_tensor` as `transfer_write_permutations_tensor_masked`.

Author: pabloantoniom