Support required paramter in Query Serializer

[MissiaL]

Added support for required and optional parameters in Query Serializer.

This will help to better understand the schema.

[codecov]

Codecov Report

Merging #12 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master      #12   +/-   ##
=======================================
  Coverage   91.09%   91.10%           
=======================================
  Files          31       31           
  Lines        1539     1540    +1     
=======================================
+ Hits         1402     1403    +1     
  Misses        137      137           

Impacted Files	Coverage Δ
drf_spectacular/openapi.py	86.48% <100.00%> (+0.02%)	⬆️
tests/test_extend_schema.py	84.00% <100.00%> (ø)

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