WelcomeScreen: putting the "icon plus link" into a component

...more links to come...

Change-Id: Ic500f38995bf515eda80c0720d1fdd7718e5ff54
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
WelcomeScreen: Adding links to Qt Account and Qt Cloud Services

Change-Id: Iec39fd4a44671c284e7442f40a1c3156a299437e
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>