Encryption support for the statement store (#14440)

* Added ECIES encryption

* tweaks

* fmt

* Make clippy happy

* Use local keystore

* qed

substrate/client/keystore/src/lib.rs

@@ -26,6 +26,7 @@ use std::io;
 /// Local keystore implementation
 mod local;
 pub use local::LocalKeystore;
+pub use sp_keystore::Keystore;
 
 /// Keystore error.
 #[derive(Debug, thiserror::Error)]