ui: Indexing UI

* Added DialogView with QtDialogView implementation to handle information dialogs
* Implemented QtIndexingDialog class that covers all different dialogs for indexing
* Directly communicate with DialogView from Prpject and all Tasks involved in indexing
* Block QtMainWindow UI while indexing

src/lib_gui/qt/element/QtStatusBar.cpp

@@ -9,6 +9,8 @@
 QtStatusBar::QtStatusBar()
     : m_text(this)
 {
+	addWidget(new QWidget()); // add some space
+
 	QMovie* movie = new QMovie((ResourcePaths::getGuiPath() + "statusbar_view/loader.gif").c_str());
 	// if movie doesn't loop forever, force it to.
 	if (movie->loopCount() != -1)