Show the merge_request approval_rules when merge request is merged

We need to remove the invalid approval rules from the list of rules that we show to the frontend. This is because the majority of these invalid rules, aren't applicable to our merge request. We need to check how we want to handle this, because sometimes a merge request will have an actual invalid rule, on the MR itself. Do we want to show them all or none?

We then have to switch to showing the merge request rules, when merged for the api.