Sort periods in AEAT 303 report

Closes #13707
(grafted from 56008996f232df54746f90ce06a1f2ac3c0c865a)

--HG--
branch : 6.0

modules/account_es/reporting_tax.py

@@ -261,7 +261,7 @@ class AEAT303(AEATReport):
         context = super().get_context(records, header, data)
         amounts = context['amounts']
 
-        periods = records
+        periods = sorted(records, key=attrgetter('start_date'))
         start_date = periods[0].start_date
         end_date = periods[-1].end_date