feat: add support for PS256, RS256 PKCV in validationClient

[kridai]

Fixes

Closes https://issues.corp.twilio.com/browse/DII-1072.
Previously, public key client validation (PKCV) only allowed RS256 algorithms to be used. This change is to support PS256 algorithm as well.

Checklist

• I acknowledge that all my contributions will be made under the project's license
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• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation about the functionality in the appropriate .md file
• I have added inline documentation to the code I modified

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[sonarqubecloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
5 Code Smells

71.4% Coverage
0.0% Duplication

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