Add a Game Franchise/Series Section#217

Add a section where every game in the library is sorted into its respective franchise. We can already see other games that belong the same franchise or series when scrolling down on a game page, so it would be a good opportunity to add this imo.

Could you also consider to use IGDB’s “franchise” attribute as described in suggestion “Series vs franchises#213“? It’s slightly different from the “series” attribute since with the former one you can basically look for “all the spyro games ever released” while with the series one you’re splitting them into the different series.