Added a chipTan dialog for the KBanking plugin

Implemented the "flicker field" ("animierte Grafik") for HandHeldDevices
(HHD) used for tan creation in chipTan-orders. Should be compatible with
the standard by Zentraler Kreditausschuss.

GUI: chipTan Tan input dialog, only visible under certain circumstances.
Only interesting for german translations as this is supported only by
german banks.