chore(Rust SDK): IggyConsumer docs

[haubur]

Description

In an effort to add and improve the Rust SDK docs (first issue: #3306 and first PR here: #3809) a follow up for the IggyConsumer.

Affected area / component

Rust SDK

Proposed solution

No response

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