Ranking tournaments functionality

Ability to create a ranking and add tournament to this ranking.
Since this is a bit more difficult since we also have individual tournaments we need to set up some guidelines.

• A tournament can be added to a ranking

• A ranking can be played in several places. Ranking tournament 1 can be at a different location as Ranking tournament 2.

• You can indicate which tournament is the final tournament

• Indicate whether the final tournament is open or only for the X-placed players

• Prizes for ranking

• Date when the ranking takes place

• Additional description for the ranking

• Instructions for the ranking

Separate menu item "Rankings" should be placed where people can filter and search for rankings. When they click on it they see all the information about the ranking but also all the tournaments themselves that they can click on.

The organizer can then choose to make these ranking tournaments also visible in the standard "Tournaments" page. This because often people just want to play darts and not so much specifically want to get the ranking.