[FIX] account,purchase,sale: Export fail when dict passed to write function

A `TypeError` traceback that occurs in `xlsxwriter.worksheet._write`
was caught by Sentry.

The problem is that there is a binary field which is used by `account`
module as a compute field with a python `dict`.

https://github.com/odoo/odoo/blob/76a640d05a350840bdde1c88bd052251aabd6b12/addons/account/models/account_move.py#L426-L431

https://github.com/odoo/odoo/blob/a542cb3b3d1232f0e2dec58a220a4b35fb76cc7f/addons/l10n_cl/models/account_move.py#L148-L163

Variables of type dict were not supported by the exporter, the solution
is to use a fix already made before in 16.0 (https://github.com/odoo/odoo/pull/105043

)
by making `tax_totals` non-exportable

opw-3086746

closes odoo/odoo#106914

Signed-off-by: Olivier Colson (oco) <oco@odoo.com>