Updated clans system

[evanpelle]

This is a master bug to track all clan related task

Clan ideas:

1. Have clan ownership / ability to transfer leadership
2. Allow clans to be closed/invite only
3. User can be member of multiple clans
4. Person can be leader of multiple clans
5. Clan warchest: winning a game under a clan tag gives that clan curency
6. clan wide cosmetics

[deshack]

Clan diplomacy, with effect on teams composition (explained a little better in this Discord thread )