Function to_grpc_insert_requests_from_spans 

pub fn to_grpc_insert_requests_from_spans(
    spans: &[TraceSpan],
    pipeline: &PipelineWay,
    pipeline_params: &GreptimePipelineParams,
    table_name: &str,
    query_ctx: &QueryContextRef,
    pipeline_handler: PipelineHandlerRef,
) -> Result<(RowInsertRequests, usize)>

Convert a subset of trace spans to GreptimeDB row insert requests.