[FIX] account: tax computation at reconciliation

- Create a tax included of 7.7%
- Set the company rounding to 'Round Globally'
- Create a bank statement of 10.70, reconcile
- Add a manual line with the 7.7% tax

An extra line of 0.01 remains.

The remaining amount after subtracting the tax is `0.00499...`, which
is rounded to `0.005` by `Math.round(total*1000)/1000`, and finally
displayed as `0.01`.

The 'Round Globally' setting makes sense for objects containing multiple
lines, such as SO, PO or invoice. In the case of a reconciliation, we
can switch to the 'Round per line' config.

opw-1837986