logic: Added update checker connecting to online API

* connects to https://www.sourcetrail.com/api/v1/versions/latest
* sends information about OS, platform, license type, current version and a unique user token
* Automatic update check is enabled via Startscreen and performed once every 24 hours on window focus
* Update check can be forced by clicking on "check for new version" on start screen
* renamed TimePoint to TimeStamp

fortune cookie message = In Träumen und im Leben ist nichts unmöglich.

src/lib_gui/qt/network/QtNetworkFactory.cpp

@@ -1,6 +1,7 @@
 #include "QtNetworkFactory.h"
 
 #include "QtIDECommunicationController.h"
+#include "QtUpdateChecker.h"
 
 QtNetworkFactory::QtNetworkFactory()
 {
@@ -11,6 +12,11 @@ QtNetworkFactory::~QtNetworkFactory()
 }
 
 std::shared_ptr<IDECommunicationController> QtNetworkFactory::createIDECommunicationController(StorageAccess* storageAccess) const
-{ 
+{
 	return std::make_shared<QtIDECommunicationController>(nullptr, storageAccess);
-}
+}
+
+std::shared_ptr<UpdateChecker> QtNetworkFactory::createUpdateChecker() const
+{
+	return std::make_shared<QtUpdateChecker>();
+}