[FIX][l10n_it_ricevute_bancarie] fix compute of tax
[FIX][l10n_it_ricevute_bancarie] fix compute of tax

When on an invoice add a line for collecting expenses or bank receipts,
set the tax value of that line as defined on the invoice fiscal position
tax mapping;
Remove unused params values on `map_tax` method call

dcorio/l10n-italy,OCA/l10n-italy,dcorio/l10n-italy,OCA/l10n-italy,dcorio/l10n-italy,OCA/l10n-italy