[Test🧪] Cover TopicMessageType property precedence

[mxsm]

Prerequisites

• I have searched existing test issues

Test Scope

File: rocketmq-model/src/topic.rs.
TopicMessageType::parse_from_message_property classifies a map using ordered message markers. The precedence has no focused test in topic.rs.

Test Cases

• TRAN_MSG set to case-insensitive true wins over delay and sharding markers.
• A delay marker wins over sharding, priority, and lite markers; TRAN_MSG=false does not force Transaction.
• Sharding wins over priority and lite; priority wins over lite; lite alone selects Lite.
• An empty map selects Normal.

Acceptance: use table-driven or similarly concise cases; preserve the existing classification order and public API.
Validation from the repository root: cargo test -p rocketmq-model --lib, cargo fmt -p rocketmq-model -- --check, and cargo clippy -p rocketmq-model --tests --no-deps -- -D warnings.

Willing to contribute?

• I can submit a PR for this