test(ui5-file-uploader): add form support samples (#12939)

fixes: #12930

Author: tsanislavgatev

packages/main/test/pages/FormSupport.html

@@ -70,11 +70,10 @@
     </form>
     <form method="get">
         <ui5-title>ui5-file-uploader</ui5-title>
-        <!-- <ui5-file-uploader id="file_uploader1"></ui5-file-uploader>
-        <ui5-file-uploader id="file_uploader2" value="&quot;Screenshot 2024-04-09 at 12.26.53.png&quot; "></ui5-file-uploader>
-        <ui5-file-uploader id="file_uploader3" name="file_uploader3"></ui5-file-uploader>
-        <ui5-file-uploader id="file_uploader4" name="file_uploader4" value="&quot;Screenshot 2024-04-09 at 12.26.53.png&quot;"></ui5-file-uploader>
-        <ui5-button id="file_uploader_btn1" submits>Submits form</ui5-button> -->
+        <ui5-file-uploader id="file_uploader1"></ui5-file-uploader>
+        <ui5-file-uploader id="file_uploader2" name="file_uploader2"></ui5-file-uploader>
+        <ui5-file-uploader id="file_uploader3" name="file_uploader3" required></ui5-file-uploader>
+        <ui5-button id="file_uploader_btn1" submits>Submits form</ui5-button>
     </form>
     <form method="get">
         <ui5-title>ui5-input</ui5-title>