Make stages, game selections queryable on GraphQL endpoint, a la videogames

[casperOne]

The title says it all really; currently, we can query the universe of videogames so that we can investigate and maintain mappings to data on our side.

However, with stages and game selections (i.e. character selections) we have to save the values that come from Smashgg and then reconcile the stage selections/game selections manually so that we can create a map.

Having the ability to query both of these upfront would eliminate the need to perform the manual evaluation step (we could define the mapping up front).