Save expanded state also for: (#2173)

- Expand all nodes
- Collapse all nodes

LibreHardwareMonitor/UI/MainForm.Designer.cs

@@ -397,7 +397,7 @@ namespace LibreHardwareMonitor.UI
             this.collpaseAllNodesMenuItem.Name = "collpaseAllNodesMenuItem";
             this.collpaseAllNodesMenuItem.Size = new System.Drawing.Size(188, 22);
             this.collpaseAllNodesMenuItem.Text = "Collapse All Nodes";
-            this.collpaseAllNodesMenuItem.Click += new System.EventHandler(this.CollapsepAllNodes_Click);
+            this.collpaseAllNodesMenuItem.Click += new System.EventHandler(this.CollapseAllNodes_Click);
             //
             // resetPlotMenuItem
             //

LibreHardwareMonitor/UI/MainForm.cs

@@ -1289,11 +1289,27 @@ public sealed partial class MainForm : Form
     private void ExpandAllNodes_Click(object sender, EventArgs e)
     {
         treeView.ExpandAll();
+
+        foreach (var node in treeView.AllNodes)
+        {
+            if (node.Tag is IExpandPersistNode expandPersistNode)
+            {
+                expandPersistNode.Expanded = true;
+            }
+        }
     }
 
-    private void CollapsepAllNodes_Click(object sender, EventArgs e)
+    private void CollapseAllNodes_Click(object sender, EventArgs e)
     {
         treeView.CollapseAll();
+
+        foreach (var node in treeView.AllNodes)
+        {
+            if (node.Tag is IExpandPersistNode expandPersistNode)
+            {
+                expandPersistNode.Expanded = false;
+            }
+        }
     }
 
     private void resetPlotMenuItem_Click(object sender, EventArgs e)