Revert of Revert of [mlir][shape] Tidy up shape.shape_of

Summary:

- Mark it NoSideEffect
- Add custom parser/printer

This reverts the temporary revert in
https://reviews.llvm.org/rG84a9c725742d26df04808a3c7349dbd98684c6cb
That was a false alarm. A downstream test actually needed to be updated.