add account_trial_balance_period_xls

cf. https://github.com/luc-demeyer/account-financial-reporting/blob/7.0/account_trial_balance_period_xls/doc/doc.rst

for functional description.
What's the problem with an overwrite of the search? If it's overwritten it is to blanket change all searches of periods.

This implementation doesn't take into account user group permissions and will also return shallow unlinked (`active = False`) periods. Is this what is indented.