module/foreign-toplevel: track outputs each toplevel is mapped on

* Bind the foreign-toplevel-manager object *after* the first round of
  global objects. This ensures we bind all pre-existing wl-output
  objects before binding the toplevel manager. This is important, since
  otherwise we wont get any output_enter() events for the initial set of
  toplevels.

* Bind xdg-output-manager, to be able to bind xdg-output objects for
  each wl-output.

* Add xdg-output-listener to each wl/xdg-output, to be able to get the
  outputs’ names.

* Add a list of outputs to each toplevel. The output_enter() event
  adds to this list, and output_leave() removes from it.

* Add option ‘all-monitors’. When not set (the default), toplevels are
  only included in the generated content if they are mapped on the same
  output as the bar itself. When *not* set, all toplevels are always
  included in the generated content.

modules/meson.build

@@ -72,7 +72,7 @@ if backend_wayland
   endforeach
 
   mod_data += {
-    'foreign-toplevel': [[ftop_proto_headers + ftop_proto_src], [dynlist]],
+    'foreign-toplevel': [[wl_proto_src + wl_proto_headers + ftop_proto_headers + ftop_proto_src], [dynlist]],
   }
 endif