style: add some type hints

[SaidBySolo]

For the typing of static, refer to the typing of FutureStatic class.

[codecov]

Codecov Report

Merging #2517 (8276c0e) into main (9cf38a0) will increase coverage by 0.053%.
The diff coverage is 100.000%.

@@              Coverage Diff              @@
##              main     #2517       +/-   ##
=============================================
+ Coverage   87.392%   87.446%   +0.053%     
=============================================
  Files           69        69               
  Lines         5560      5560               
  Branches       966       966               
=============================================
+ Hits          4859      4862        +3     
+ Misses         509       507        -2     
+ Partials       192       191        -1     

Impacted Files	Coverage Δ
sanic/app.py	88.718% <ø> (ø)
sanic/mixins/routes.py	93.700% <ø> (ø)
sanic/response.py	89.119% <ø> (ø)
sanic/config.py	98.591% <100.000%> (ø)
sanic/server/protocols/http_protocol.py	83.823% <0.000%> (+2.205%)	⬆️

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