feat: Add extensibility for tmtv and segmentation modes (#6128)

* feat: Add extensibility for tmtv and segmentation modes

* Fixes for ordering issues on laod

* Remove unnecessary reference lookup

* Chane side panel timing to fix tests

* PR comments - change how mode definitions get created

* Improvements to mode customizations

* Start organizing customizations

* Misc fixes for a customization demo page

* Security fixes

* PR requested changes to naming

platform/app/public/customizations/tools/measurementLabels.jsonc

@@ -0,0 +1,23 @@
+// Example URL-loaded customization: measurementLabels
+//
+// Makes the viewer prompt for a label from a fixed list whenever a measurement
+// is created (key: `measurementLabels`). `labelOnMeasure` triggers the prompt on
+// creation and `exclusive` restricts entries to the provided items.
+//
+// Load it with `?customization=tools/measurementLabels`.
+{
+  "global": {
+    "measurementLabels": {
+      "$set": {
+        "labelOnMeasure": true,
+        "exclusive": true,
+        "items": [
+          { "value": "Head", "label": "Head" },
+          { "value": "Shoulder", "label": "Shoulder" },
+          { "value": "Knee", "label": "Knee" },
+          { "value": "Toe", "label": "Toe" }
+        ]
+      }
+    }
+  }
+}