Function run_bandwidth_test 

pub async fn run_bandwidth_test<F, Fut>(
    client: Client,
    server: &Server,
    test_label: &str,
    is_verbose: bool,
    test_fn: F,
) -> Result<TestRunResult, Error>
where
    F: FnOnce(Arc<Tracker>) -> Fut,
    Fut: Future<Output = Result<(f64, f64, u64, Vec<f64>), Error>>,

Run a bandwidth test with latency-under-load monitoring.

This is a template method that handles:

• Progress bar setup
• Background latency monitoring
• Test execution via the provided closure
• Result aggregation

Arguments

• client - HTTP client to reuse
• server - Server to test against
• test_label - Label for progress display
• is_verbose - Whether to show visible progress
• test_fn - Async closure that runs the actual bandwidth test

Errors

Returns Error if the test fails.