Add rustfmt.toml and cargo fmt (#23238)

* fmt

* formatted

Co-authored-by: Lucas B <buffalu@jito.network>

banks-client/src/lib.rs

@@ -5,8 +5,10 @@
 //! but they are undocumented, may change over time, and are generally more
 //! cumbersome to use.
 
-pub use crate::error::BanksClientError;
-pub use solana_banks_interface::{BanksClient as TarpcClient, TransactionStatus};
+pub use {
+    crate::error::BanksClientError,
+    solana_banks_interface::{BanksClient as TarpcClient, TransactionStatus},
+};
 use {
     borsh::BorshDeserialize,
     futures::{future::join_all, Future, FutureExt, TryFutureExt},