Outliner - Notify on GP Layer Change

This adds NA_SELECTED to notifier when selecting Grease Pencil layers so Properties Editor will update

Differential Revision: https://developer.blender.org/D5073

Reviewed by Dalai Felinto

source/blender/editors/space_buttons/space_buttons.c

@@ -510,7 +510,7 @@ static void buttons_area_listener(wmWindow *UNUSED(win),
     case NC_GPENCIL:
       switch (wmn->data) {
         case ND_DATA:
-          if (ELEM(wmn->action, NA_EDITED, NA_ADDED, NA_REMOVED)) {
+          if (ELEM(wmn->action, NA_EDITED, NA_ADDED, NA_REMOVED, NA_SELECTED)) {
             ED_area_tag_redraw(sa);
           }
           break;

source/blender/editors/space_outliner/outliner_draw.c

@@ -806,7 +806,7 @@ static void namebutton_cb(bContext *C, void *tsep, char *oldname)
           BLI_uniquename(
               &gpd->layers, gpl, "GP Layer", '.', offsetof(bGPDlayer, info), sizeof(gpl->info));
 
-          WM_event_add_notifier(C, NC_GPENCIL | ND_DATA, gpd);
+          WM_event_add_notifier(C, NC_GPENCIL | ND_DATA | NA_SELECTED, gpd);
           break;
         }
         case TSE_R_LAYER: {