♻️ uniformize with other sdks

[sebastianMindee]

Description

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Requires a change to the official Guide documentation.

[Copilot]

Pull request overview

This PR aims to “uniformize” the Python SDK with other Mindee SDKs by adding typed accessors to SimpleField, introducing a polling cancellation mechanism in the V2 client, and strengthening URL input validation against common SSRF vectors.

Changes:

• Added string_value / number_value / boolean_value convenience properties on SimpleField + unit tests.
• Added a CancellationToken and optional cancellation_token support in Client.enqueue_and_get_result.
• Replaced the URL scheme check with a more complete validate_url_for_source SSRF-focused validation.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/v2/parsing/test_simple_field.py	Adds unit coverage for the new typed SimpleField accessors.
tests/v2/file_operations/test_split_operation_integration.py	Removes a stray blank line in an integration test.
mindee/v2/parsing/inference/field/simple_field.py	Introduces typed getters that validate the stored value’s type.
mindee/v2/client.py	Adds optional cancellation token support during polling.
mindee/mindee_http/response_validation.py	Adds validate_url_for_source for SSRF-oriented URL validation.
mindee/mindee_http/cancellation_token.py	Introduces a small cancellation token class.
mindee/input/url_input_source.py	Uses validate_url_for_source instead of a simple https prefix check.