Tickets: reports, bug reports, suggestions and applications

Tickets were the most requested thing since the Discord bot came out, and they're finally here.

• Ticket types. Player reports, bug reports, suggestions, staff applications and a general contact form. Turn on whichever ones you want for each experience.
• Player commands in Discord: /reportplayer, /bugreport, /suggest, /apply, /appeal and /ticket.
• Ticket panels. /setupticketchannel posts a panel with buttons, so players don't have to remember commands.
• Attachments on tickets, stored safely and viewable from the dashboard.
• Pings. Choose which roles get pinged for each ticket type.
• Auto-close for tickets that have gone quiet.

A few smaller things came along with it. /setlogchannel can now send a single category of logs to a channel, so moderation, staff and ticket logs can each go somewhere different. There are in-app notifications for things that need your attention, and you can exclude specific members from role sync.