Implemented If only one category, skip category chooser

This has been implemented for Sportsbook Index page (Category pages already bypass the category chooser.)

If there is only 1 viewable category for the viewing user, the "Add event" button will take the viewing user directly to the Add Event input form bypassing the Category Chooser.

Note: There are a couple other places where the "Add event" button is displayed where Category data is not being fetched (like in the Find New system for example). Those buttons will continue to launch the category chooser as I won't be adding additional queries just to bypass the category chooser.