[#83211730] Fixing TeamSnap event webhooks.

- Fixed an issue where adding a group to an existing event would not trigger the correct actions.
- Fixed an issue where multiple events would be created for a unique event, if a game was made with more than one competitor.
- Fixed an issue where the response was not being decoded correctly after sending an initial request to TeamSnap for a game event with competitors.
- Moved group check to TeamSnap webhook template and added check to each unique webhooks `process()`
- Fixed typos in comments

Requires: https://github.com/AllPlayers/allplayers-mainline/pull/4118
Assuming that this wasn't working at all before, this should have been caught in testing before it made it to prod. Are the webhooks not part of our regression testing cycle?