Function insert_plugin_message 

pub async fn insert_plugin_message(
    pool: &Pool,
    owner: &str,
    name: &str,
    version: &str,
    agent_instance_hierarchy: &str,
    response_id: Option<&str>,
    created_at: i64,
    line: &str,
) -> Result<(), Error>

INSERT one captured stderr line for a plugins run invocation.