Replace `responsive` with `intab` for better remdering og panel in a tab

Related feedback:
- https://github.com/uBlockOrigin/uBlock-issues/issues/2116#issuecomment-1143634719

platform/common/vapi-background.js

@@ -812,7 +812,7 @@ vAPI.setIcon = (( ) => {
 browser.browserAction.onClicked.addListener(function(tab) {
     vAPI.tabs.open({
         select: true,
-        url: `popup-fenix.html?tabId=${tab.id}&responsive=1`,
+        url: `popup-fenix.html?tabId=${tab.id}&intab=1`,
     });
 });