[Rust] Support LiteSimpleConsumer

## Feature Request

The Rust SDK currently only has `LitePushConsumer` (push-style lite consumption, added in #1227). It is missing `LiteSimpleConsumer` (pull-style lite consumption).

Java (#1188) and Go (#1314) already implement `LiteSimpleConsumer`. This issue tracks adding it to the Rust SDK so all languages reach parity for lite pull consumption.

## Proposal

- Add `LiteSimpleConsumer` and `LiteSimpleConsumerTrait`.
- Add `ClientType::LiteSimpleConsumer = 6`.
- Add lite-topic-aware queue selection for lite consumers.
- Fix ack/change-invisible-duration to pass through the message's lite topic so acks route to the correct LMQ consume queue.
- Add an example (`examples/lite_simple_consumer.rs`).

Start by reading the existing Rust LitePushConsumer and LitePushConsumerTrait, then compare the Java and Go LiteSimpleConsumer implementations referenced in the issue. Trace Rust client type selection, lite-topic-aware queue selection, and ack/change-invisible-duration routing. Done means the new consumer and trait work, the example exists, and lite pull consumption reaches the correct queues.

Written by the indexing model from the issue text.