[python sdk] Expose Permissions and the remaining user auth methods

[ethanlin01x]

Description

Follow-up to #3682, as scoped there. The Python SDK can now create, update, and delete users, but every user is created without permissions: create_user in foreign/python/src/client.rs hardcodes None for the permissions argument, and there is no way to grant or inspect permissions afterwards. update_permissions, change_password, and logout_user from the Rust UserClient trait (core/common/src/traits/user_client.rs) are also still unexposed, and UserInfoDetails returned by get_user has no permissions getter.

This means Python still cannot provision non-root service accounts end to end. A deployment script can create a user but cannot give it access to anything.

Affected area / component

Python SDK

Proposed solution

Mirror the Rust domain types (core/common/src/types/permissions/permissions_global.rs) as PyO3 classes and complete the UserClient surface:

• Expose Permissions, GlobalPermissions, StreamPermissions, and TopicPermissions as Python classes. All fields are booleans plus two nested dicts (streams: dict[int, StreamPermissions], topics: dict[int, TopicPermissions]), so the mapping is mechanical.
• Add the optional permissions parameter to create_user, replacing the hardcoded None.
• Add update_permissions(user_id, permissions), change_password(user_id, current_password, new_password), and logout_user() on IggyClient.
• Add a permissions getter on UserInfoDetails so granted permissions round-trip through get_user.

Alternatives considered

No response

Contribution

• I'm willing to submit a pull request to implement this feature

Good first issue

• I think this could be a good first issue for a new contributor