Add native go line parser implementation to go-audit

[mwielgoszewski]

• I've read and understood the Contributing guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've been mindful about doing atomic commits, adding documentation to my changes, not refactoring too much.
• I've a descriptive title and added any useful information for the reviewer. Where appropriate, I've attached a screenshot and/or screencast (gif preferrably).
• I've written tests to cover the new code and functionality included in this PR.
• I've read, agree to, and signed the Contributor License Agreement (CLA).

PR Summary

This PR implements a native lineparser (javascript implementation originally written by @nbrownus) directly into go-audit.

For performance reasons, it is turned off by default, but may be switched on via two configuration options under message_decoding:

message_decoding:
  enabled: true
  human_friendly_messages: true

enabled simply performs basic line parsing. human_friendly_messages extends this parsing to construct human-friendly messages based on the contents of an audit message.

[codecov-io]

Codecov Report

Merging #62 into master will decrease coverage by 28.3%.
The diff coverage is 6.34%.

@@            Coverage Diff             @@
##           master     #62       +/-   ##
==========================================
- Coverage   75.21%   46.9%   -28.31%     
==========================================
  Files           5       6        +1     
  Lines         476     776      +300     
==========================================
+ Hits          358     364        +6     
- Misses        101     393      +292     
- Partials       17      19        +2

Impacted Files	Coverage Δ
client.go	89.23% <ø> (ø)	⬆️
lineparser.go	0% <0%> (ø)
parser.go	89.61% <100%> (ø)	⬆️
writer.go	73.33% <100%> (ø)	⬆️
audit.go	74.48% <50%> (-0.41%)	⬇️
marshaller.go	51.13% <75%> (-0.12%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update daf7385...d43dd35. Read the comment docs.

[glaslos]

FYI this mapping is kernel and architecture specific.

[CLAassistant]

All committers have signed the CLA.

[mwielgoszewski]

@wadey what would it take to get this merged?

[codecov-commenter]

Codecov Report

Merging #62 into master will decrease coverage by 28.30%.
The diff coverage is 6.34%.

@@             Coverage Diff             @@
##           master      #62       +/-   ##
===========================================
- Coverage   75.21%   46.90%   -28.31%     
===========================================
  Files           5        6        +1     
  Lines         476      776      +300     
===========================================
+ Hits          358      364        +6     
- Misses        101      393      +292     
- Partials       17       19        +2     

Impacted Files	Coverage Δ
client.go	89.23% <ø> (ø)
lineparser.go	0.00% <0.00%> (ø)
audit.go	74.48% <50.00%> (-0.41%)	⬇️
marshaller.go	51.13% <75.00%> (-0.12%)	⬇️
parser.go	89.61% <100.00%> (ø)
writer.go	73.33% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update daf7385...d43dd35. Read the comment docs.