[mlir][transforms] Add a topological sort utility and pass

This patch adds a topological sort utility and pass. A topological sort reorders
the operations in a block without SSA dominance such that, as much as possible,
users of values come after their producers.

The utility function sorts topologically the operation range in a given block
with an optional user-provided callback that can be used to virtually break cycles.
The toposort pass itself recursively sorts graph regions under the target op.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D125063