feat(dpi_ng/consent): add Data Privacy Integration NextGen Consent service integration to sdk

[Ashwith-N]

Disclaimer: Do not include SAP-internal or customer-specific information in this PR (e.g. internal system URLs, customer names, tenant IDs, or confidential configurations). This is a public repository.

Description

To introduce the sap_cloud_sdk.core.dpi_ng.consent capability to the SAP Cloud SDK for Python. It provides a unified API for managing consents, purposes, templates, retention rules, and configuration reference data exposed by the DPI NextGen Consent Repository OData V4 service.

Key components included:

• Client Factory: A public create_client() function with a typed ConsentClient API
• Authentication strategies: BearerTokenAuth, ClientCredentialsAuth, and ClientCertificateAuth (mTLS)
• Request/Result Models: Typed DTOs for consent operations
• Service layer: Five service attributes (consents, purposes, templates, retention, configuration) each covering full CRUD and lifecycle operations against the respective OData endpoints.
• Exception hierarchy: ConsentSDKError base with typed subclasses for 401, 403, 400/422, 404, 409, and other OData errors.
• Documentation: Module guidance in user-guide.md.
• Test coverage: Unit tests and BDD integration tests under tests/core/unit/dpi_ng/consent and tests/core/integration/dpi_ng/consent

Related Issue

N/A

Type of Change

Please check the relevant option:

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Code refactoring
• Dependency update

How to Test

1. Install dependencies: uv sync --all-extras
2. Configure credentials per docs/INTEGRATION_TESTS.md
3. Run unit tests: uv run pytest tests/core/unit/dpi_ng/consent/ -v
4. Run integration tests: uv run pytest tests/core/integration/dpi_ng/consent/ -v
5. Expected result: all tests pass

Checklist

Before submitting your PR, please review and check the following:

• I have read the Contributing Guidelines
• I have verified that my changes solve the issue
• I have added/updated automated tests to cover my changes
• All tests pass locally
• I have verified that my code follows the Code Guidelines
• I have updated documentation (if applicable)
• I have added type hints for all public APIs
• My code does not contain sensitive information (credentials, tokens, etc.)
• I have followed Conventional Commits for commit messages

Breaking Changes

If this PR introduces breaking changes, please describe:

• What breaks
  None.
• Migration path for users
  No migration required.
• Alternative approaches considered
  N/A

Additional Notes

This feature follows the existing SDK module structure described in CONTRIBUTING.md and aligns with the integration test setup documented in INTEGRATION_TESTS.md. It is intended as an additive capability and does not change existing public APIs.

[cla-assistant]

All committers have signed the CLA.