fix(Core/DungeonFinder): misc improvements (#7488)

- Players should be able to enter the same dungeon if just completed it
- Properly define if the proposal is new
- Set teleport point to the nearest graveyard if teleported to dungeon from other instance
- Display completed encounters when joining LFG in progress (excluding random)
- Closes #5914
- Closes #7388

src/server/game/Handlers/LFGHandler.cpp

@@ -151,7 +151,7 @@ void WorldSession::HandleLfgTeleportOpcode(WorldPacket& recvData)
     recvData >> out;
 
     LOG_DEBUG("network", "CMSG_LFG_TELEPORT [%s] out: %u", GetPlayer()->GetGUID().ToString().c_str(), out ? 1 : 0);
-    sLFGMgr->TeleportPlayer(GetPlayer(), out, true);
+    sLFGMgr->TeleportPlayer(GetPlayer(), out);
 }
 
 void WorldSession::HandleLfgPlayerLockInfoRequestOpcode(WorldPacket& /*recvData*/)