Adds Snowbridge to Rococo runtime (#2522)

# Description

Adds Snowbridge to the Rococo bridge hub runtime. Includes config
changes required in Rococo asset hub.

---------

Co-authored-by: Alistair Singh <alistair.singh7@gmail.com>
Co-authored-by: ron <yrong1997@gmail.com>
Co-authored-by: Vincent Geddes <vincent.geddes@hey.com>
Co-authored-by: claravanstaden <Cats 4 life!>

bridges/snowbridge/parachain/primitives/core/tests/mod.rs

@@ -0,0 +1,14 @@
+#[cfg(test)]
+mod tests {
+	use frame_support::traits::Contains;
+	use snowbridge_core::AllowSiblingsOnly;
+	use xcm::prelude::{Junction::Parachain, Junctions::X1, MultiLocation};
+
+	#[test]
+	fn allow_siblings_predicate_only_allows_siblings() {
+		let sibling = MultiLocation::new(1, X1(Parachain(1000)));
+		let child = MultiLocation::new(0, X1(Parachain(1000)));
+		assert!(AllowSiblingsOnly::contains(&sibling), "Sibling returns true.");
+		assert!(!AllowSiblingsOnly::contains(&child), "Child returns false.");
+	}
+}