Restore BauweltMember cache and notify all dev servers on member changes

getBauMember never read its cache after the Exposed migration, so every
scoreboard render hit the DB (Too many connections, #479). Cache by
(bauwelt, member) incl. negative results, evict on addMember/remove, and
send BaumemberUpdatePacket to the Bauserver and all dev servers (also on
addmember). BauMemberUpdate clears the cache itself to not depend on
handler order.

BauSystem/BauSystem_Main/src/de/steamwar/bausystem/features/world/BauMemberUpdate.java

@@ -28,6 +28,7 @@ import de.steamwar.bausystem.utils.bossbar.BossBarService;
 import de.steamwar.linkage.Linked;
 import de.steamwar.network.packets.PacketHandler;
 import de.steamwar.network.packets.server.BaumemberUpdatePacket;
+import de.steamwar.sql.BauweltMember;
 import io.papermc.paper.event.player.PlayerPickBlockEvent;
 import org.bukkit.Bukkit;
 import org.bukkit.boss.BarColor;
@@ -57,6 +58,8 @@ public class BauMemberUpdate extends PacketHandler implements Listener {
     }
 
     public static void baumemberUpdate() {
+        // Packet handlers run in no guaranteed order, so don't rely on CoreNetworkHandler having cleared the cache yet.
+        BauweltMember.clear();
         Set<Player> newSpectator = new HashSet<>();
         Set<Player> newBuilder = new HashSet<>();
         Bukkit.getOnlinePlayers().forEach(player -> {