McuSupport: Register Qt for MCUs examples

This change introduces the registration of examples (or rather demos) of
the Qt for MCUs SDK at the launch time of Qt Creator.

This presumes that either the SDK installer set the Qt for MCUs SDK path
(which is the default use-case) or that the user selected/changed the
SDK path in a prior run of Qt Creator.

Task-number: UL-1218
Change-Id: I6484d3e3065f501da4cd6faccfe02605003f6cbf
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mcusupport/mcusupportplugin.cpp

@@ -76,6 +76,7 @@ bool McuSupportPlugin::initialize(const QStringList& arguments, QString* errorSt
     dd = new McuSupportPluginPrivate;
 
     McuSupportOptions::registerQchFiles();
+    McuSupportOptions::registerExamples();
     ProjectExplorer::JsonWizardFactory::addWizardPath(
                 Utils::FilePath::fromString(":/mcusupport/wizards/"));