When having an invoice in foreign currency and a partial payment in
domestic currency (in a different date with a different exchange rate),
the computed amount due is incorrect. When computing the
amount_residual_currency the payment (in domestic currency) is converted
to the foreign currency using the exchange rate of the invoice date, and
not the one of the payment date (see 56d92213).

If the account.partial.reconcile line will have a currency_id and a
amount_currency the amount_residual_currency will not be converted but
simply added.

This behaviour was introduced with e1306066
and backported to version 11.0 with 3363d723.
In version 12.0 this behaviour was partially reverted in d3d26120.

opw-2156001

closes odoo/odoo#44181

X-original-commit: 94d34e052f3757c21884fd5a57cc68ea8c51aafb
Signed-off-by: Jorge Pinna Puissant (jpp) <jpp@odoo.com>