Add wxutil::getBitmap() helper function

Add a simple utility function to replace the very common and somewhat verbose
combination of wxArtProvider::GetBitmap and IUIManager::ArtIdPrefix.

libs/wxutil/bitmap.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "iuimanager.h"
+
+#include <wx/artprov.h>
+
+namespace wxutil
+{
+
+/**
+ * \brief
+ * Get a wxBitmap from the art provider
+ *
+ * \param name
+ * Image file name with no prefix, e.g. "something.png"
+ */
+wxBitmap getBitmap(const std::string& name)
+{
+    return wxArtProvider::GetBitmap(GlobalUIManager().ArtIdPrefix() + name);
+}
+
+}

plugins/dm.gameconnection/GameConnection.cpp

@@ -15,6 +15,7 @@
 #include "imainframe.h"
 
 #include "scene/Traverse.h"
+#include "wxutil/bitmap.h"
 
 #include <sigc++/signal.h>
 #include <sigc++/connection.h>
@@ -310,8 +311,7 @@ void GameConnection::addToolbarItems()
 
         // Add a toggle for the camera sync function
         auto tool = camTB->AddTool(
-            wxID_ANY, "L",
-            wxArtProvider::GetBitmap(GlobalUIManager().ArtIdPrefix() + "sr_icon_communication.png"),
+            wxID_ANY, "L", wxutil::getBitmap("sr_icon_communication.png"),
             _("Enable game camera sync with DarkRadiant camera")
         );
         _camSyncToggle->connectToolItem(tool);