Allow specify schedule dispatch origin (#6387)

* allow specify schedule dispatch origin

* fix tests

* use caller origin for scheduled

* fix tests

* line width

* check origin for cancel

* line width

* fix some issues for benchmarking

* fix doc test

* another way to constraint origin

* fix build issues

* fix cancel

* line width

* fix benchmarks

* bump version

* enable runtime upgrade

* add migration code and test

* Update frame/scheduler/src/lib.rs

Co-authored-by: Gavin Wood <github@gavwood.com>

* expose migration method

* add notes

* bump version

* remove on_runtime_upgrade

* fix test

Co-authored-by: Gavin Wood <github@gavwood.com>

substrate/frame/system/src/lib.rs

@@ -301,7 +301,7 @@ pub struct EventRecord<E: Parameter + Member, T> {
 }
 
 /// Origin for the System module.
-#[derive(PartialEq, Eq, Clone, RuntimeDebug)]
+#[derive(PartialEq, Eq, Clone, RuntimeDebug, Encode, Decode)]
 pub enum RawOrigin<AccountId> {
 	/// The system itself ordained this dispatch to happen: this is the highest privilege level.
 	Root,