Add Language and Judge endpoints to API v2

[Ninjaclasher]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1471 into master will increase coverage by 0.02%.
The diff coverage is 72.72%.

@@            Coverage Diff             @@
##           master    #1471      +/-   ##
==========================================
+ Coverage   45.84%   45.87%   +0.02%     
==========================================
  Files         208      208              
  Lines       11968    11979      +11     
==========================================
+ Hits         5487     5495       +8     
- Misses       6481     6484       +3     

Impacted Files	Coverage Δ
dmoj/urls.py	89.47% <ø> (ø)
judge/views/api/api_v2.py	49.01% <72.72%> (+1.35%)	⬆️

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[Xyene]

Thanks!