Parameter and header get value refactor

[p1c2u]

No description provided.

[codecov]

Codecov Report

Merging #677 (890ae99) into master (0da2a38) will increase coverage by 0.09%.
The diff coverage is 97.43%.

@@            Coverage Diff             @@
##           master     #677      +/-   ##
==========================================
+ Coverage   91.24%   91.34%   +0.09%     
==========================================
  Files         126      126              
  Lines        3542     3559      +17     
  Branches      423      423              
==========================================
+ Hits         3232     3251      +19     
+ Misses        262      261       -1     
+ Partials       48       47       -1     

Files Changed	Coverage Δ
openapi_core/schema/parameters.py	96.96% <ø> (+4.66%)	⬆️
openapi_core/validation/response/validators.py	78.72% <83.33%> (ø)
openapi_core/validation/validators.py	95.00% <98.33%> (+0.60%)	⬆️
openapi_core/templating/media_types/finders.py	100.00% <100.00%> (ø)
...enapi_core/unmarshalling/response/unmarshallers.py	79.84% <100.00%> (ø)
openapi_core/unmarshalling/unmarshallers.py	85.36% <100.00%> (ø)
openapi_core/validation/request/validators.py	86.79% <100.00%> (ø)