Unify & enforce same interface of sr-io (std & without-std) (#2381)

* WiP: HTTP Apis.

* Working on the API.

* Add docs, clean up the API.

* Expose ext_ stuff as well.

* Implement HTTP helpers for offchain sr-io.

* Remove HTTP stuff.

* Remove spurious leading `::`

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Rename in toml.

* Add issue number.

* Bump version.

substrate/node/runtime/src/lib.rs

@@ -59,7 +59,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	impl_name: create_runtime_str!("substrate-node"),
 	authoring_version: 10,
 	spec_version: 66,
-	impl_version: 66,
+	impl_version: 67,
 	apis: RUNTIME_API_VERSIONS,
 };