Support Match Day and Campus DLCs

[kaenganxt]

General changes:

• Don't show DLC warning popup anymore
• Instead, display DLC support when starting server or joining game (next to the mod support)
• Ignore christmas DLC when joining as it only adds music
• Sync district style (e.g. for European Suburbia Content Creator pack)
• Make IgnoreHelper thread local (otherwise the "ignore" state could overlap between simulation and UI thread)
• Detect sync problems by checking if the IgnoreHelper is still in ignoring mode after the simulation tick (in simulation thread) or if it is active in Unity engine's LateUpdate lifecycle method (in UI thread).
• This should detect (and partly fix) cases where an exception occurs between start and end ignore.

Match Day DLC:

• Fix ticket prize synchronization
• Synchronize result of football events

Campus DLC:

• Sync all interactions in the campus management panel (buying grant, setting academic staff, cheerleading budget, coaches count, ticket prices, varsity color and varsity identity)
• Sync district park policies (=Campus Area policies and more)
• Sync campus upgrades and statistics when the academic year ends