[WIP] Add initial implementation for netcat

[rdzhou]

Main features of netcat is added. The rest remains to be added.

[mssun]

• Please add [WIP] prefix in the title if you think it is not ready for reviewing/merging.
• The PR didn't pass the CI because of testing (try to run cargo test first). You can add a testing file (test_nc.rs) to bypass the check.

[codecov[bot]]

Codecov Report

Merging #28 into master will decrease coverage by 1.98%. The diff coverage is 0%.

@@            Coverage Diff             @@
##           master      #28      +/-   ##
==========================================
- Coverage   19.95%   17.96%   -1.99%     
==========================================
  Files          46       47       +1     
  Lines        4680     5198     +518     
  Branches     1081     1274     +193     
==========================================
  Hits          934      934              
- Misses       3355     3873     +518     
  Partials      391      391

Impacted Files	Coverage Δ
libmesabox/src/lib.rs	59.01% <ø> (ø)	:arrow_up:
libmesabox/src/networking/nc/mod.rs	0% <0%> (ø)

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[mssun]

I plan to refactor your code. Could you help me to write some integration tests? Thanks.