Removes Snowbridge parachain directory (#3186)

Removes the `bridges/snowbridge/parachain` directory and moves
everything up to under `snowbridge` directly. We are cleaning up our
local dev env after merging our crates into the polkadot-sdk.

---------

Co-authored-by: claravanstaden <Cats 4 life!>

bridges/snowbridge/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, Location};
+
+	#[test]
+	fn allow_siblings_predicate_only_allows_siblings() {
+		let sibling = Location::new(1, [Parachain(1000)]);
+		let child = Location::new(0, [Parachain(1000)]);
+		assert!(AllowSiblingsOnly::contains(&sibling), "Sibling returns true.");
+		assert!(!AllowSiblingsOnly::contains(&child), "Child returns false.");
+	}
+}