0029571: Samples: build qt samples together with OCCT

Extending CMake procedure by 'BUILD_MODULE_QtSamples' variable to switch on qt samples build.
Implementation required:
- union of occt_toolkit_tool.cmake and occt_toolkit.cmake files;
- correction of qt samples sources by adding path to Qt 'plugins' folder. It helps to avoid definition of additional variable (QT_QPA_PLATFORM_PLUGIN_PATH) when staring sample.bat for qt samples;
- executable processing is extended in cmake procedure by providing 'EXECUTABLE_PROJECT' variable. Now we need not specify custom processing for DRAWEXE in occt_toolkit.cmake

samples/qt/Interface/src/Application.cxx

@@ -6,6 +6,8 @@
 #include <stdlib.h>
 #include <QMdiSubWindow>
 
+#include <OSD_Environment.hxx>
+
 ApplicationWindow::ApplicationWindow()
     : ApplicationCommonWindow( ),
       myImportPopup( 0 ),
@@ -210,8 +212,10 @@ void ApplicationWindow::onSelectionChanged()
 QString ApplicationWindow::getIEResourceDir()
 {
   static QString aResourceDir =
-    QString::fromUtf8 (qgetenv ("CSF_IEResourcesDefaults").constData());
-  
+    QString (OSD_Environment ("CSF_IEResourcesDefaults").Value().ToCString());
+  if (aResourceDir.isEmpty())
+    aResourceDir = QString (OSD_Environment ("CSF_OCCTResourcePath").Value().ToCString()) + "/samples";
+
   return aResourceDir;
 }