Generate storage info for pallet im_online (#9654)

* Integrating WrapperOpaque from PR #9738

* Adding storage_info to pallet im-online
Changing some `Vec` to `WeakBoundedVec`
Adding the following bounds:
* `MaxKeys
* `MaxPeerInHeartbeats`
* `MaxPeerDataEncodingSize`
to limit the size of `WeakBoundedVec`

* Fix syntax

* Need to clone keys

* Changes in formatting

substrate/primitives/runtime/src/testing.rs

@@ -18,7 +18,7 @@
 //! Testing utilities.
 
 use crate::{
-	codec::{Codec, Decode, Encode},
+	codec::{Codec, Decode, Encode, MaxEncodedLen},
 	generic,
 	scale_info::TypeInfo,
 	traits::{
@@ -59,6 +59,7 @@ use std::{
 	Deserialize,
 	PartialOrd,
 	Ord,
+	MaxEncodedLen,
 	TypeInfo,
 )]
 pub struct UintAuthorityId(pub u64);