feat(services): EAN 13 generation

templates/contract/en.html

@@ -55,7 +55,7 @@
         </div>
         <div class="column">
           <img style="vertical-align: revert; margin-top: auto; object-fit: cover; max-height: 2cm;"
-            src="{{/* TODO: BARCODE*/}}" />
+            src="data:image/png;base64,{{ barcode .ID}}" />
         </div>
       </div>
       <div class="columns" style="padding-top: 1rem;">