erp5_web_renderjs_ui: add compatibility with the page css class

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_nojqm_css.css

@@ -1193,6 +1193,9 @@ div[data-gadget-scope='header'] .ui-header ul {
 .gadget-content .invisible > .ui-field-contain > label {
   display: none;
 }
+.gadget-content .page {
+  background-color: #FFFFFF;
+}
 @media only screen and (min-width: 45em) and (max-width: 85em), not screen and (max-width: 85em) {
   .gadget-content .ui-field-contain {
     display: flex;

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_nojqm_css.xml

@@ -246,7 +246,7 @@
                   </item>
                   <item>
                       <key> <string>serial</string> </key>
-                      <value> <string>989.18940.32400.648</string> </value>
+                      <value> <string>989.27549.43950.31078</string> </value>
                   </item>
                   <item>
                       <key> <string>state</string> </key>
@@ -264,7 +264,7 @@
                           </tuple>
                           <state>
                             <tuple>
-                              <float>1610465136.37</float>
+                              <float>1611220748.32</float>
                               <string>UTC</string>
                             </tuple>
                           </state>

bt5/erp5_web_renderjs_ui/SkinTemplateItem/portal_skins/erp5_web_renderjs_ui/erp5css.less.txt

@@ -1379,6 +1379,10 @@ div[data-gadget-scope='header'] .ui-header {
     // used to hide the label of a formbox
     display: none;
   }
+  .page {
+    // backward-compatibility: force non transparency on such field
+    background-color: @colorbackground;
+  }
 
 
   @media @tablet, @desktop {