Remove FTOverwriteConfirmationDialog
This removes FTOverwriteConfirmationDialog
(and its usage) and replaces it where necessary.
Additionally, one NonModalConfirmationDialog
in filetransfers.py is replaced by NewConfirmationDialog
This removes FTOverwriteConfirmationDialog
(and its usage) and replaces it where necessary.
Additionally, one NonModalConfirmationDialog
in filetransfers.py is replaced by NewConfirmationDialog