feat(typing): add type hints to compiled router

[CaselIT]

This is mainly to try how cython works with pep484 types

NOTE: this is currently unmergiable, since it's not py 3.5 compatible

Gist with the compilations with cython https://gist.github.com/CaselIT/f0493d74422cce46c95c10e8abd1e4f0

[codecov]

Codecov Report

Merging #1944 (8e4adf1) into master (e255bff) will decrease coverage by 0.24%.
The diff coverage is 93.33%.

@@             Coverage Diff             @@
##            master    #1944      +/-   ##
===========================================
- Coverage   100.00%   99.75%   -0.25%     
===========================================
  Files           63       63              
  Lines         6610     6611       +1     
  Branches      1067     1068       +1     
===========================================
- Hits          6610     6595      -15     
- Misses           0       12      +12     
- Partials         0        4       +4     

Impacted Files	Coverage Δ
falcon/routing/compiled.py	98.73% <93.33%> (-1.27%)	⬇️
falcon/asgi/__init__.py	81.81% <0.00%> (-18.19%)	⬇️
falcon/util/__init__.py	95.55% <0.00%> (-4.45%)	⬇️
falcon/util/misc.py	96.64% <0.00%> (-3.36%)	⬇️
falcon/media/multipart.py	98.82% <0.00%> (-1.18%)	⬇️

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[vytas7]

This should be good to revisit again once #1947 gets merged.

[vytas7]

@CaselIT Now we can continue with this one; we just need to address merge conflicts and it may possible to move this forward off Draft.

[CaselIT]

I'll try getting into it soonish