Trigger webhook for more than one unresolved discussion in merge requests
## Problem to Solve In https://gitlab.com/gitlab-org/gitlab/-/issues/26234 a webhook was added that triggered when all discussions were resolved. A corresponding trigger for discussions be unresolved still needs to be added. ## Proposal Instead of triggering a webhook for _each_ unresolved thread event, we should only trigger the webhook one time if the number of unresolved threads is going from `0` to more than `1`.
issue