[llvm] [mlir] [MLIR][Python] Add shard Dialect Python Bindings (PR #162578)

[Siavash Nazari via llvm-commits]

Svoch wrote:

@makslevental - Can you PTAL once more? The tests are updated and I've added an additional verification step to make sure we're actually building correct IR. IMO, we should be good to go.

https://github.com/llvm/llvm-project/pull/162578