Show volume on the gas analyzer (#25720)

The gas analyzer now shows the volume of pipes, tanks, canisters and the environment.

Adjust gas analyzers so that the volume and number of moles shown corresponds to only the scanned element, e.g. a canister or single pipe in a pipenet.

Content.Client/Atmos/UI/GasAnalyzerWindow.xaml.cs

@@ -163,6 +163,26 @@ namespace Content.Client.Atmos.UI
             parent.AddChild(panel);
             panel.AddChild(dataContainer);
 
+            // Volume label
+            var volBox = new BoxContainer { Orientation = BoxContainer.LayoutOrientation.Horizontal };
+
+            volBox.AddChild(new Label
+            {
+                Text = Loc.GetString("gas-analyzer-window-volume-text")
+            });
+            volBox.AddChild(new Control
+            {
+                MinSize = new Vector2(10, 0),
+                HorizontalExpand = true
+            });
+            volBox.AddChild(new Label
+            {
+                Text = Loc.GetString("gas-analyzer-window-volume-val-text", ("volume", $"{gasMix.Volume:0.##}")),
+                Align = Label.AlignMode.Right,
+                HorizontalExpand = true
+            });
+            dataContainer.AddChild(volBox);
+
             // Pressure label
             var presBox = new BoxContainer { Orientation = BoxContainer.LayoutOrientation.Horizontal };