Added XQuery Tool and refactored tools-service (#220)

Co-authored-by: Adam Bem <adam.bem@zoho.eu>
Reviewed-on: #220
Reviewed-by: Mikolaj Widla <widlam@noreply.example.com>

Frontend/assets/scripts/tools/xquery.js

@@ -0,0 +1,13 @@
+/**
+ * This function is executed after the page is loaded.
+ * 
+ * @function
+ * @name init
+ * @kind function
+ */
+function init() {
+    // Make sure that only plain text is pasted
+    configurePastingInElement("xmlArea");
+    configurePastingInElement("transformArea");
+
+}