`show_all` call from `Tray::update` attempts to walk the widget tree and
make every widget visible. Since we control individual tray item
visibility based on `Status` SNI property, we don't want that to happen.
Modify `Tray::update` to control the visibility of a whole tray module
only and ensure that the children of `Item` are still visible when
necessary.
On the `Passive` value of `Status` tray items would be hidden unless
`show-passive-items` is set to true.
On the `NeedsAttention` value of `Status` tray items will have a
`.needs-attention` CSS class.
It seems that dbusmenu is not ready to display menu immediately and
needs some time to sync data via DBus.
Fixes LIBDBUSMENU-GLIB-CRITICAL: dbusmenu_menuitem_send_about_to_show:
assertion 'DBUSMENU_IS_MENUITEM(mi)' failed.
Also fixes initial render of the menu with layer shell popups support patch.
Set ItemIsMenu to true by default because libappindicator supports
neither ItemIsMenu nor Activate method and compiant SNI implementations
are expected to reset the flag during initial property fetch.
To be revisited if anyone finds the implementation that has Activate
but does not set ItemIsMenu.