Facelift for token game

[0xUnicorn]

After rewriting most of the token game before last years event, different issues showed up when going in production, so we need a facelift before this years event.

This is an issue for managing these tasks.

• TokenCategory list and detail views show tokens from all camps and not only for the current camp.
• Last join and Latest find should have a default value when None.
• When no tokens has been created show a Token game has not started yet, check back later message.
• Text color not adjusting for white color scheme on Total players and Total finds widgets.
• Improve the fix from: a8ef129 and add tests.
• Add 'random token generator' for auto generating new token string when creating tokens
• Refactor Camp methods for generating checked_in tickets and participant_count (include support for Add attendance to past camps on camp list #1319)
• Graphs sometimes don't load when refreshing dashboard page except when changing the viewport like having the developer console open (happens in both firefox/brave)