Consecutive games that are edited need to be updated

After #28 lands, we need to add some logic to the update mechanism that allows us to find games that are "linked" together. For example, if a two-game set is entered into Arbitrator, the second game will not have a start time with 30+ minutes ahead of it (for prep time). This is fine, but if the first game is subsequently edited to no longer be before the second game (i.e. on a different day or something), then we need to make sure that the second game has its start time adjusted.

Start with the update mechanism and the changes from issue #28. Trace how consecutive or linked games are identified when the first game is edited, then verify that a formerly consecutive second game has its start time adjusted when the games are no longer on the same sequence.

Written by the indexing model from the issue text.