Spectators

[xenonca]

Finally add a working spectator mod(e) for staff. I've made two PRs for CTF V2 to fix the encountered issues which were approved by a bunch of people and they were for some incomprehensible reason still refused to being merged. This should IMO include:

• visual invisibility, ofc not only but especially when joining the game
• not being pointable
• a /watch command that doesn't get the spectator uncovered when the watched player does /m
• no join or leave messages
• do not show full privs list of spectators to normal players
• do not show spectators in /team, /who or /status
• exclude spectators from the match summary or rankings if possible
• anything else?
  Conclusio: Spectators should be completely inexistant to normal players
  Maybe you can use this as some kind of checklist @olliy1or as I've seen you've been working on a new PR already.

[olliy1or]

Finished tasks from #25 (comment)

• visual invisibility, ofc not only but especially when joining the game
• not being pointable
• a /watch command that doesn't get the spectator uncovered when the watched player does /m
• no join or leave messages
• exclude spectators from the match summary or rankings if possible

[LoneWolfHT]

• Spectator sometimes loses invisibility when at /unwatch or a new match
• Nametag sometimes shows up(?)

[magnetar47]

• Spectator join/leave messages are posted on IRC, and subsequently relayed to Discord.