Implemented XML Formatter and simplified structure of XML tools (#229)

Co-authored-by: Adam Bem <adam.bem@zoho.eu>
Reviewed-on: #229
Reviewed-by: Mikolaj Widla <widlam@noreply.example.com>

Frontend/src/assets/sampleXQuery.xquery

@@ -1,7 +1,5 @@
-declare namespace p="http://www.release11.com/person";
-declare namespace b="http://www.release11.com/book";
-declare namespace l="http://www.release11.com/library";
+declare default element namespace "http://www.release11.com/schemas/Sample.xsd";
+declare namespace u = "http://www.release11.com/schemas/Sample.xsd";
 
-
-for $x in //p:person
-return string($x/p:name)
+for $x in /u:root/u:UserList[@Id = 'a']/u:User
+return string($x/u:Name)