test: add test_grouped_emitters

[tkrs]

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[Copilot]

Pull Request Overview

This PR introduces a new test for validating the grouped_emitters functionality and updates the grouped_emitters method to accept an optional size parameter.

• Modified grouped_emitters to accept Option
• Removed redundant size calculation in the flush logic
• Added a test case verifying grouped_emitters behavior

Comments suppressed due to low confidence (1)

src/queue.rs:63

• [nitpick] The variable name 'mes_len' could be renamed to 'message_len' for improved clarity.

        let mes_len = self.messages.len();