Do not hide panel when launching an application if the mouse is on the panel
Need Functions.itemUnderMouse because MouseArea.containsMouse returns true when tapping (i.e. no mouse used) on it.
Unfortunately the QML testlib do not set the proper value when issueing a mouseMove so i can't add a test that proofs it works, i'll try to propose something upstream and then add the test at a later MR (LP: #1591311)