KRACOEUS-8348: Changes to Meeting Minutes are not saved

Had to add a "merge" functionality to the process of saving minutes, because existing code only tracked new additions to the minutes, which were added to a refreshed list of old minutes.
The deepCopy is only to save off a copy of the currently "active" minutes, so the base collection of minutes can be refreshed to pick up changes from other users.

Previously we would throw away any changes to the minutes when we refreshed the collection of minutes.

Yes, in the case of 2 users modifying the same minute, last-in wins. I am thinking this would be exceedingly rare, as (I think) only the author and admin can edit. Refactoring to lock the minutes would be costly, and making the minutes read-only would be hard on the users.