Now loading barcode format from env with overwrite via query param

ref #13

src/templates/sponsoring_contract.html

@@ -55,7 +55,7 @@
         </div>
         <div class="column">
           <img style="vertical-align: revert; margin-top: auto; object-fit: cover; max-height: 2cm;"
-            src="{{--bc this.id 'ean13'}}" />
+            src="{{--bc this.id ../codeformat}}" />
         </div>
       </div>
       <div class="columns" style="padding-top: 1rem;">