[Runtime] Bound XCMP queue (#2302)

Remove `without_storage_info` from the XCMP queue pallet. Part of
https://github.com/paritytech/polkadot-sdk/issues/323

Changes:
- Limit the number of channels that can be suspended at the same time.
- Limit the number of channels that can have messages or signals pending
at the same time.

A No-OP migration is put in place to ensure that all `BoundedVec`s still
decode and not truncate after upgrade. The storage version is thereby
bumped to 4 to have our tooling remind us to deploy that migration.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>

cumulus/pallets/xcmp-queue/src/tests.rs

@@ -520,7 +520,7 @@ fn hrmp_signals_are_prioritized() {
 		});
 
 		// But a signal gets prioritized instead of the messages:
-		XcmpQueue::send_signal(sibling_para_id.into(), ChannelSignal::Suspend);
+		assert_ok!(XcmpQueue::send_signal(sibling_para_id.into(), ChannelSignal::Suspend));
 
 		let taken = XcmpQueue::take_outbound_messages(130);
 		assert_eq!(