[FIX] PEP8 and convention for l10n_ch_base_bank
[FIX] PEP8 and convention for l10n_ch_dta
[FIX] PEP8 and convention for l10n_ch
[FIX] PEP8 and convention for l10n_ch_payment_slip
[FIX] PEP8 and convention for l10n_ch_sepa
[FIX] PEP8 and convention for l10n_ch_scan_bvr