Clonable Client to async order

[lamrongol]

Only add #[derive(Clone)], to order in another thread.
Example:

let c = client.clone();
tokio::spawn(async move {
    let order =
        c.issue::<order::Create>(&request).await.unwrap();
});
``

[lamrongol]

Errors of auto test occurs where I didn't change like following, please check

error: doc list item overindented
   --> src/api/v2/account.rs:123:7
    |
123 |   ///      power (the default for all non-pattern-day-trader accounts
    |       ^^^^^ help: try using `  ` (2 spaces)
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.93.0/index.html#doc_overindented_list_items
    = note: `-D clippy::doc-overindented-list-items` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::doc_overindented_list_items)]`