Extract unsigned tx from the SignParam structure (#1561)

* change sign_transaction method

* clippy

* rustup update && clippy

* remove redudnant clone

bridges/relays/utils/src/lib.rs

@@ -25,6 +25,15 @@ use futures::future::FutureExt;
 use std::time::Duration;
 use thiserror::Error;
 
+/// Default relay loop stall timeout. If transactions generated by relay are immortal, then
+/// this timeout is used.
+///
+/// There are no any strict requirements on block time in Substrate. But we assume here that all
+/// Substrate-based chains will be designed to produce relatively fast (compared to the slowest
+/// blockchains) blocks. So 1 hour seems to be a good guess for (even congested) chains to mine
+/// transaction, or remove it from the pool.
+pub const STALL_TIMEOUT: Duration = Duration::from_secs(60 * 60);
+
 /// Max delay after connection-unrelated error happened before we'll try the
 /// same request again.
 pub const MAX_BACKOFF_INTERVAL: Duration = Duration::from_secs(60);