Internalise third-party dependencies

(cherry picked from commit 725eb619b4)

webassets/js/utils.js

@@ -0,0 +1,33 @@
+//
+// GENERAL UTILITY FUNCTIONS
+// OBject, string manipulation etc.
+//
+
+// Utility function to escape HTML characters from a string.
+function escapeHtml(str) {
+    if (typeof str !== 'string') {
+        return '';
+    }
+
+    const escapeCharacter = (match) => {
+        switch (match) {
+            case '&': return '&';
+            case '<': return '&lt;';
+            case '>': return '&gt;';
+            case '"': return '&quot;';
+            case '\'': return '&#039;';
+            case '`': return '&#096;';
+            default: return match;
+        }
+    };
+
+    return str.replace(/[&<>"'`]/g, escapeCharacter);
+}
+
+// Converts an HTML hex colour to an array of [R, G, B] where each is 0-255.
+function hexToRGB(hex) {
+    return hex.replace(/^#?([a-f\d])([a-f\d])([a-f\d])$/i
+             ,(m, r, g, b) => '#' + r + r + g + g + b + b)
+    .substring(1).match(/.{2}/g)
+    .map(x => parseInt(x, 16));
+}