Cases in the Installer, IFW, and MT smoke test suite

Installer, IFW, and MT smoke test suite should contain the following cases that are currently in the IFW Smoke set:

tst_verify_ifw_and_maintenancetool_sha 
tst_silent_update --> check: this should test also the silent install. Add this, if it's missing.
tst_qbsp 
tst_fetch_categories 
tst_install_with_sudo_update_with_normal_user 
tst_installer_performance 
tst_oss_mirror 
tst_localization 
+ tst_ui_functions

Also: https://bugreports.qt.io/browse/QTIFW-3451 Test maintenance tool update