feat: easier websocket interface annotation

[SaidBySolo]

close #2437

[codecov]

Codecov Report

Merging #2438 (0125c79) into main (cc97287) will increase coverage by 0.002%.
The diff coverage is 100.000%.

@@              Coverage Diff              @@
##              main     #2438       +/-   ##
=============================================
+ Coverage   87.135%   87.138%   +0.002%     
=============================================
  Files           60        60               
  Lines         5045      5046        +1     
  Branches       908       908               
=============================================
+ Hits          4396      4397        +1     
  Misses         477       477               
  Partials       172       172               

Impacted Files	Coverage Δ
sanic/__init__.py	100.000% <100.000%> (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 cc97287...0125c79. Read the comment docs.

[ahopkins]

Thanks @SaidBySolo

[thibautd]

Thanks @SaidBySolo !