Corrects how Indian GSTR-1 and GSTR-3B reports calculate and display tax base values. This ensures nil-rated values appear correctly in GSTR-1 and prevents GSTR-3B from failing to open when it relies on those tax base calculations.

In GSTR-1 and GSTR-3B report if we domain_formula then label is balance but we have lable tax_base

So GSTR-1 nill rated not show value and GSTR-3B is not open because tax_base is use in aggregation formula

This fixes an issue in financial reports where certain positive or negative sum calculations could incorrectly show as 0.0. Businesses using these report formulas will now see the intended values, improving accuracy in accounting reports.

The domain engine wasn't processing -sum_if_pos and -sum_if_neg correctly. It will always display 0.0 because it didn't recognize the subformula properly.

Signed-off-by: Ruben Gomes <rugo@odoo.com>