Updated fw_filters template

• Added support for cases when SRC and DST prefexis are not defined, but from protocol and ports are - e.g. IPv4 Traceroute term.
• Updated structure for "special cases" of term.from.protocol
• Updated structure for main block (src/dst prefix lists)

requested review from @simone.spinelli

assigned to @Aleksandr.Kurbatov

mentioned in commit 90a607a6

merged