Unify CO/Matchgrid Select listing and CO/Matchgrid Index (to edit) listing

There is concern about having two separate screens for matchgrid selection due to potential confusion for admins, e.g.

• The selector on first login:
  • /match/matchgrids/select
  • Can only select a CO or matchgrid to manage.
• The superuser list of matchgrids:
  • /match/matchgrids
  • Can edit OR select a CO or matchgrid to manage.

If only the latter were rendered, no matter how we got here the behavior would be the same - the extra actions on the rows would only appear for the appropriate (e.g. platform) admin, and the main link would be to the “Manage” screen, not to the “edit” screen - though this is a different behavior from most other index listings.

If it is possible for the comanage CO’s listing to behave like this, making this change is pretty achievable: that is, the comanage CO’s listing of COs would need to be presented to the user at first login, with regular users being only able to select which CO to launch.

Look at this from the PE perspective, and then see if we can roll such a change into Match.

The primary advantage of this is for admins who can see both views: no matter how they get to this index, it will always look and behave the same way.