Eliminate O(n^2) status removal in DashboardTreeTableModel

updateChannelNodes called statuses.remove(status) inside a loop over
child nodes. With an ArrayList, each remove is O(n), making the update
O(channels × statuses). Collected matched statuses in a HashSet and
called removeAll once after the loop, reducing to O(n + m).

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

Author: NicoPiel

client/src/com/mirth/connect/client/ui/DashboardTreeTableModel.java

@@ -498,13 +498,14 @@ private void updateChannelNodes(List<DashboardStatus> statuses, MutableTreeTable
     }
 
     private void updateChannelNodes(Map<String, DashboardStatus> statusMap, List<DashboardStatus> statuses, MutableTreeTableNode parent) {
+        Set<DashboardStatus> matched = new HashSet<>();
         for (int i = 0; i < parent.getChildCount(); i++) {
             AbstractDashboardTableNode node = (AbstractDashboardTableNode) parent.getChildAt(i);
 
             if (statusMap.containsKey(node.getDashboardStatus().getKey())) {
                 // Remove channels that do exist from the list of statuses so they will not be added again later.
                 DashboardStatus status = statusMap.get(node.getDashboardStatus().getKey());
-                statuses.remove(status);
+                matched.add(status);
                 // Update the channel status
                 node.setDashboardStatus(status);
                 modelSupport.firePathChanged(new TreePath(getPathToRoot(node)));
@@ -513,6 +514,7 @@ private void updateChannelNodes(Map<String, DashboardStatus> statusMap, List<Das
                 updateConnector(statusMap, node);
             }
         }
+        statuses.removeAll(matched);
     }
 
     private void removeLingeringChannelNodes(List<DashboardStatus> statuses, MutableTreeTableNode root) {