Clean up sr-io (#3609)

* Move trait `Printable` into `sr-primitives`

* Cleanup runtime io trie_root interfaces

* Remove last generic bits from sr-io interface

* Fix srml-sudo after master merge

* Fix benchmarks

* Runtime bump

substrate/srml/contracts/src/wasm/runtime.rs

@@ -822,7 +822,7 @@ define_env!(Env, <E: Ext>,
 	ext_println(ctx, str_ptr: u32, str_len: u32) => {
 		let data = read_sandbox_memory(ctx, str_ptr, str_len)?;
 		if let Ok(utf8) = core::str::from_utf8(&data) {
-			runtime_io::print(utf8);
+			sr_primitives::print(utf8);
 		}
 		Ok(())
 	},