Add refactored loss based controller

[mengelbart]

Adds the loss-based component of the refactored congestion controller. The relevant section from the internet-draft is here: https://datatracker.ietf.org/doc/html/draft-ietf-rmcat-gcc-02#section-6

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (65cf7f1) to head (286e427).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@              Coverage Diff              @@
##           master       #25        +/-   ##
=============================================
+ Coverage        0   100.00%   +100.00%     
=============================================
  Files           0         1         +1     
  Lines           0        31        +31     
=============================================
+ Hits            0        31        +31     

Flag	Coverage Δ
go	100.00% <100.00%> (?)

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[JoTurk]

Thank you, and sorry for missing track of this change.

[mengelbart]

No worries, I realize it is hard to review a huge change, such as #2, at once. This will hopefully make it easier to follow, and having more people looking at this and understanding the reasoning is much better. Thanks for the fast review!