Python SDK: expose get_me, get_client and get_clients

[justinmclean]

Description

The Rust client can report the currently connected client and enumerate all connected clients (core/common/src/traits/system_client.rs). The Python SDK exposes none of it, so a Python operator cannot see connection state that every other SDK can. Part of the parity work tracked in #3893.

async fn get_me(&self) -> Result<ClientInfoDetails, IggyError>;
async fn get_client(&self, client_id: u32) -> Result<Option<ClientInfoDetails>, IggyError>;
async fn get_clients(&self) -> Result<Vec<ClientInfo>, IggyError>;

get_client and get_clients require permission to read server info; get_me requires authentication only.

Affected area / component

Python SDK

Proposed solution

• Add foreign/python/src/client_info.rs wrapping ClientInfo and ClientInfoDetails, following src/user.rs (pyclass + From conversions + gen_stub_pyclass), and register it in src/lib.rs.
• Add the three methods to src/client.rs. get_client returns None when the id is unknown rather than raising.
• Add the stub entries to foreign/python/apache_iggy.pyi.
• Add foreign/python/tests/test_client_info.py: assert get_me() returns the connected client, that its id appears in get_clients(), and that get_client() on an unknown id returns None.

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

[yummyPancake2607]

i would like to work on this issue

[slbotbm]

@yummyPancake2607 assigned