Add team system and team-based win condition

Introduce a full in-memory team system and integrate it into gameplay and UI.

- Add Team, TeamManager, TeamListener and TeamCommand to manage teams, invites, accept/deny, leave, kick and info. TeamManager stores teams and pending invites (INVITE_TTL_MS) using concurrent maps and exposes helper/query methods (areInSameTeam, allAliveInSameTeam, getInviterFor, cleanExpiredInvites, reset).
- Wire TeamManager into SpeedHG: initialize, schedule periodic invite cleanup, register command and listener, and reset teams on plugin disable.
- Update GameManager to consider teams for win conditions, build team winner names, exclude teammates from random teleport/compass logic, and credit all winning team members for stats/ranking.
- Move ability charge feedback out of individual kits into KitEventDispatcher: remove per-kit onFullyCharged overrides and add centralized ActionBar/sound feedback (sendChargeUpdateActionBar/sendChargeReadyActionBar). ActiveAbility no longer defines onFullyCharged.
- Make OraclePerk ignore teammates when finding nearest enemy.
- Add config entries for teams and corresponding language strings; tweak some default values in CustomGameSettings (gladiator arena radius/height and minor formatting changes).

These changes enable 2-player teams (configurable), friendly-fire prevention, invite lifecycle handling, and team-aware endgame logic.

src/main/resources/plugin.yml

@@ -34,4 +34,7 @@ commands:
     permission: speedhg.admin.ranking
   perks:
     description: 'Perk-Auswahl öffnen'
-    usage: '/perks'
+    usage: '/perks'
+  team:
+    description: 'Team-System for SpeedHG'
+    usage: '/team <invite|accept|deny|leave|kick|info> [player]'