feat(azure/service-principal): support migration parity inputs

[KYasko]

Summary

• add optional service principal input app_role_assignment_required
• add optional application api input requested_access_token_version
• allow optional display_name override per kubernetes federation entry
• wire these inputs into azuread_service_principal, azuread_application (api block), and federated credential display names

Why

These inputs are needed to migrate existing identities to this module without plan regressions:

• preserve existing service principal assignment behavior
• satisfy AzureAD validation for personal-account audiences (token version 2)
• preserve legacy federated credential naming to avoid churn/replacements

Backward compatibility

• all new inputs are optional and default to current behavior
• existing module consumers should see no behavior change unless new inputs are set