Rewrite chord to be more idiomatic, prevent locks
Rewrite chord to be more idiomatic, prevent locks

The manner in which the chord was written was causing chord_unlock
loops in large shapes, see https://github.com/WikiWatershed/model-my-watershed/issues/3446#issuecomment-1005131838.

By writing it in a more idiomatic way, as other chains are written,
we fix the chord issues.

WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed,WikiWatershed/model-my-watershed