Switzerland changes its rates at the beginning of next year,
this change already has some implications on client's flow so
we add them to the localization so they can coexist with old rates till
the end of the year.
Changes:
- Added new taxes (2.5% -> 2.6%, 3.7% -> 3.8%, 7.7% -> 8.1%)
- Added tax fiscal positions to match those taxes
- Added tax groups
- Adds migration script to l10n_ch to apply those changes

Task: 3162286
Part-of: odoo/odoo#121225