[OPA] Fix OPA middleware to comply with OPA V1

[stoyanovskydmitry]

• Add support to validate policy before and after the request with IMiddlewareContext (access to input arguments)
• Add OPA request extensions handler support
• Fix unit tests
• Actualize OPA middleware support

There is no known assoicated bug number, only discussion here: https://hotchocolategraphql.slack.com/archives/CD9TNKT8T/p1739806911182499

Partially related ticket #5541.

[CLAassistant]

All committers have signed the CLA.

[michaelstaib]

Hey @stoyanovskydmitry,

this PR looks very good ... I will merge it today if all tests are green. Thank you a lot for work on this. I will integrate it with the next preview of HotChocolate 15.1

[stoyanovskydmitry]

It looks like something wrong with OPA tests env:
System.IO.DirectoryNotFoundException : Could not find a part of the path '/home/runner/work/graphql-platform/graphql-platform/src/HotChocolate/AspNetCore/test/AspNetCore.Authorization.Opa.Tests/bin/Debug/net9.0/policies/has_age_defined.rego'.
As far as I understand fix should be done on the env side, if not please let me know what should be fixed on the PR's side.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.15%. Comparing base (95ef2c4) to head (d9bf5b2).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8084      +/-   ##
==========================================
+ Coverage   74.02%   74.15%   +0.13%     
==========================================
  Files        2664     2665       +1     
  Lines      140319   140322       +3     
  Branches    16338    16323      -15     
==========================================
+ Hits       103873   104059     +186     
+ Misses      30879    30683     -196     
- Partials     5567     5580      +13     

Flag	Coverage Δ
unittests	74.15% <ø> (+0.13%)	⬆️

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[michaelstaib]

This is now integrated into 15.1.0-p.17