Fix: [AEA-4902] - use a different mock oidc app per environment

[anthony-nhs]

Summary

• Routine Change

Details

• use a different mock oidc app per environment
• use a different cis2 oidc client app per environment
• use a different key for signing requests in each environment
• use different token exchange endpoints depending on token issuer
• refactor common code to single location

[github-actions]

Deployed URL: https://cpt-ui-pr-272.dev.eps.national.nhs.uk

[sonarqubecloud]

Quality Gate passed

Issues
34 New issues
0 Accepted issues

Measures
0 Security Hotspots
87.9% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud