Don't require module name in inherents (#6576)

* Start

* Cleanup `construct_runtime!`

* Add tests

* Fix after merge

* Update the docs

Author: bkchr

src/lib.rs

@@ -894,7 +894,7 @@ pub trait Trait: frame_system::Trait + SendTransactionTypes<Call<Self>> {
 	type ElectionLookahead: Get<Self::BlockNumber>;
 
 	/// The overarching call type.
-	type Call: Dispatchable + From<Call<Self>> + IsSubType<Module<Self>, Self> + Clone;
+	type Call: Dispatchable + From<Call<Self>> + IsSubType<Call<Self>> + Clone;
 
 	/// Maximum number of balancing iterations to run in the offchain submission.
 	///