Work on refactoring measurements out of Lesion Tracker package

- Removed AssociatedStudies Collection
- Measurement API is generated from configuration files
- Data exchange methods are defined in configuration

Packages/ohif-viewerbase/client/components/viewer/gridLayout/gridLayout.js

@@ -0,0 +1,47 @@
+import { OHIF } from 'meteor/ohif:core';
+import { Template } from 'meteor/templating';
+
+Template.gridLayout.helpers({
+    // Get the height percentage for each viewport
+    height() {
+        const instance = Template.instance();
+        const rows = instance.data.rows || 1;
+        return 100 / rows;
+    },
+
+    // Get the width percentage for each viewport
+    width() {
+        const instance = Template.instance();
+        const columns = instance.data.columns || 1;
+        return 100 / columns;
+    },
+
+    // Return the viewports list
+    viewports() {
+        const instance = Template.instance();
+        const rows = instance.data.rows;
+        const columns = instance.data.columns;
+        const numViewports = rows * columns;
+        const viewportData = instance.data.viewportData;
+        const numViewportsWithData = viewportData.length;
+
+        // Check if the viewportData length is different from the given
+        if (numViewportsWithData < numViewports) {
+            // Add the missing viewports
+            var difference = numViewports - numViewportsWithData;
+            for (var i = 0; i < difference; i++) {
+                viewportData.push({
+                    viewportIndex: numViewportsWithData + i + 1,
+                    rows,
+                    columns
+                });
+            }
+        } else if (numViewportsWithData > numViewports) {
+            // Remove the additional viewports
+            return viewportData.slice(0, numViewports);
+        }
+
+        // Return the viewports
+        return viewportData;
+    }
+});