Refactor sr_primitives. (#3214)

* refactor sr_primitives.

* Fix try build error.

* Line-width

* Ui test.

* Final fixes.

* Fix build again.

* bring back ui test.

* Fix unsigned import.

* Another ui fix.

* Also refactor substrate-primitives

* Fix benchmarks.

* Fix doc test.

* fix doc tests

substrate/node/primitives/src/lib.rs

@@ -20,7 +20,7 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use runtime_primitives::{
+use sr_primitives::{
 	generic, traits::{Verify, BlakeTwo256}, OpaqueExtrinsic, AnySignature
 };