Add support for early exit walk methods.

Add support for early exit walk methods.

This is done by providing a walk callback that returns a WalkResult. This result is either `advance` or `interrupt`. `advance` means that the walk should continue, whereas `interrupt` signals that the walk should stop immediately. An example is shown below:

auto result = op->walk([](Operation *op) {
  if (some_invariant)
    return WalkResult::interrupt();
  return WalkResult::advance();
});

if (result.wasInterrupted())
  ...;

PiperOrigin-RevId: 266436700