FW_filters template reworked

• Added support for term.log statement
• Added additional checks for if term.from.protocol is defined
• Added section for the case where DST prefix list is defined, but SRC prefix list not (e.g. DF_DENY in PE CPM filters).

requested review from @simone.spinelli

assigned to @Aleksandr.Kurbatov

merged

mentioned in commit fe37ef36