Implement OSPFv3 packet layer

[mraerino]

Supports decoding and encoding of OSPFv3 messages in IPv6 packets.

RFC: 5340 - OSPF for IPv6

Test suite

Testing is based on packet captures from packetlife - in fixtures

Decoding

Decodes all packets from the capture. Only fails on unexpected conditions (length or checksum mismatch).

Encoding

Encodes go structs from snapshots in fixtures/packets. Compares the results to the packet capture.
To update the snapshots, run go run ./protocols/ospf/packetv3/fixtures/packets/gen/.

[codecov-io]

Codecov Report

Merging #235 into master will decrease coverage by 0.11%.
The diff coverage is 57.66%.

@@            Coverage Diff             @@
##           master     #235      +/-   ##
==========================================
- Coverage   59.16%   59.04%   -0.12%     
==========================================
  Files         137      141       +4     
  Lines        7412     8012     +600     
==========================================
+ Hits         4385     4731     +346     
- Misses       2848     3075     +227     
- Partials      179      206      +27

Impacted Files	Coverage Δ
protocols/ospf/packetv3/lsa.go	45.62% <45.62%> (ø)
protocols/ospf/packetv3/lsa_prefix.go	50% <50%> (ø)
protocols/ospf/packetv3/common.go	60.71% <60.71%> (ø)
protocols/ospf/packetv3/packet.go	77.66% <77.66%> (ø)

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[codecov-commenter]

Codecov Report

Merging #235 into master will decrease coverage by 0.09%.
The diff coverage is 57.66%.

@@            Coverage Diff             @@
##           master     #235      +/-   ##
==========================================
- Coverage   59.02%   58.92%   -0.10%     
==========================================
  Files         137      141       +4     
  Lines        7571     8171     +600     
==========================================
+ Hits         4469     4815     +346     
- Misses       2921     3148     +227     
- Partials      181      208      +27     

Impacted Files	Coverage Δ
protocols/ospf/packetv3/lsa.go	45.62% <45.62%> (ø)
protocols/ospf/packetv3/lsa_prefix.go	50.00% <50.00%> (ø)
protocols/ospf/packetv3/common.go	60.71% <60.71%> (ø)
protocols/ospf/packetv3/packet.go	77.66% <77.66%> (ø)

---

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Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5c05983...f08fc96. Read the comment docs.