strict bound more panel object to fix flicker

I also want more fix for other object flicker. like

    #appMenu-popup,
    #downloads-button-autohide-panel,
    #appMenu-notification-popup,
    #panic-button-success-notification,
    #unified-extensions-panel {
        max-width: 100vw !important;
    }

(this fixes unifiedExtensions-panel flicker for me) panel id from: https://github.com/mozilla/gecko-dev/blob/master/browser/components/customizableui/content/panelUI.inc.xhtm