Utility to normalize memrefs with non-identity layout maps

- introduce utility to convert memrefs with non-identity layout maps to
  ones with identity layout maps: convert the type and rewrite/remap all
  its uses

- add this utility to -simplify-affine-structures pass for testing
  purposes

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Closes tensorflow/mlir#104

COPYBARA_INTEGRATE_REVIEW=https://github.com/tensorflow/mlir/pull/104 from bondhugula:memref-normalize f2c914aa1890e8860326c9e33f9aa160b3d65e6d
PiperOrigin-RevId: 266985317