Merge pull request #9409 from camptocamp/backport/9393-to-master

[Backport master] Lazy load legend images

Author: sbrunner

src/layertree/component.html

@@ -39,6 +39,7 @@
       <img
         ng-if="::(legendIconUrl=gmfLayertreeCtrl.getLegendIconURL(layertreeCtrl))"
         ng-src="{{::legendIconUrl}}"
+        loading="lazy"
       />
     </div>
   </a>