Add Username and preferred_username to JwtTokenGenerator

[mohityadav766]

Describe your changes:

Fixes

I worked on ... because ...

Type of change:

• Bug fix
• Improvement
• New feature
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation

Checklist:

• I have read the CONTRIBUTING document.
• My PR title is Fixes <issue-number>: <short explanation>
• I have commented on my code, particularly in hard-to-understand areas.
• For JSON Schema changes: I updated the migration scripts or explained why it is not needed.

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Summary by Gitar

• OIDC compliance enhancement:
  • Added USERNAME and PREFERRED_USERNAME constants in JWTTokenGenerator.java for standard OIDC claim names
  • Embedded username and preferred_username claims in generated JWT tokens using the userName parameter for compatibility with OIDC/OAuth2 identity providers

_{This will update automatically on new commits.}

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[github-actions]

Failed to cherry-pick changes to the 1.11.4 branch.
Please cherry-pick the changes manually.
You can find more details here.

[pmbrull]

picked manually

[sonarqubecloud]

Quality Gate passed for 'open-metadata-ingestion'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud