Accessibility: Alerts the user how many results have been returned on a tree search (#10100)

* Added support for screeen reader alerts on the embed so that assitive technology knows when a url retrieve has been succesfull.
Added labels for the controls
Preview reload only triggered if the values for height and width change

* Tree search details the number of search items returned

* Add French translations

src/Umbraco.Web.UI/Umbraco/config/lang/en.xml

@@ -2577,4 +2577,8 @@ To manage your website, simply open the Umbraco backoffice and start adding cont
     <key alias="viewPublishedContentAcceptButton">View published version</key>
     <key alias="viewPublishedContentDeclineButton">Stay in preview mode</key>
   </area>
+  <area alias="treeSearch">
+    <key alias="searchResult">item returned</key>
+    <key alias="searchResults">items returned</key>
+  </area>
 </language>

src/Umbraco.Web.UI/Umbraco/config/lang/en_us.xml

@@ -2596,4 +2596,8 @@ To manage your website, simply open the Umbraco backoffice and start adding cont
     <key alias="viewPublishedContentAcceptButton">View published version</key>
     <key alias="viewPublishedContentDeclineButton">Stay in preview mode</key>
   </area>
+  <area alias="treeSearch">
+    <key alias="searchResult">item returned</key>
+    <key alias="searchResults">items returned</key>
+  </area>
 </language>

src/Umbraco.Web.UI/Umbraco/config/lang/fr.xml

@@ -2372,4 +2372,8 @@ Pour gérer votre site, ouvrez simplement le backoffice Umbraco et commencez à
         ]]>
     </key>
   </area>
+  <area alias="treeSearch">
+    <key alias="searchResult">élément retrouvé</key>
+    <key alias="searchResults">éléments retrouvés</key>
+  </area>
 </language>