[16.0] [MIG] `l10n_ch_bank`

[ivantodorovich]

• Re-download and re-format the bank csv.
• Remove useless columns from import.
• Update README with instructions on how to do it.

Depends on:

• https://github.com/OCA/l10n-switzerland/pull/686

[yvaucher]

The purpose of this module was to provide BIC for banks. However, it was only required for ISR / ISR-B. And the list of bank might be quite outdated.

I suggest to drop that module too.