Remove old sha module import code
[#2369] [GTKUI] Fix bypassing tray password dialog

Created a generic password dialog and moved the unlock code out of
systemtray so any call to window.present will now show the dialog.

Also fixed the appindicator not showing the correct visible status
[GTKUI] Fix quitting bypassing password lock
[GTKUI] Flake8 mainwindow
[GTKUI] Typo causing password dialog to show