Allow host to hide game from search

[Jacob-Griffin]

When introducing a search function, it was important to me that games were only searchable with some indication that you took part in that game. To that end, I added a "Search as", which limits search results to games including that username.

This works well, but without someone like me who uses the same name every time, this kind of falls apart. An idea:

Your "Search As" name gets added to the list of usernames that get put in the search result, and therefore no matter what username you use in the game, your "search as" will match the new games you play thereafter. A change like this should be tutorialized so that people know about it before playing.

Backpedaling on the "Search as" approach in general, see comment

[Jacob-Griffin]

Given that this adds a layer of complexity that's a bit much for search, this doesn't really feel like a good enhancement anymore. I do still think that people should have the option to opt out of their game being discoverable to the internet though, so I'll repurpose this issue:

• [ ] Host can opt to hide game from search before the game starts (visible in search is default)
• [ ] Setting to always host that way if wanted
• [ ] Setting is carried through the game, and passed onto the stored game
• [ ] Search indexing function can invalidate games that are marked as "hide from search"