Update createAffineComputationSlice to generate single result affine maps

- Update createAffineComputationSlice to generate a sequence of single result
  affine apply ops instead of one multi-result affine apply
- update pipeline-data-transfer test case; while on this, also update the test
  case to use only single result affine maps, and make it more robust to
  change.

PiperOrigin-RevId: 230965478