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/scripts/benchmark.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+# Example command for updating pallet benchmarking
+pushd ../cumulus
+cargo run --release --bin polkadot-parachain \
+--features runtime-benchmarks \
+-- \
+benchmark pallet \
+--chain=bridge-hub-rococo-dev \
+--pallet=snowbridge_pallet_ethereum_client \
+--extrinsic="*" \
+--execution=wasm --wasm-execution=compiled \
+--steps 50 --repeat 20 \
+--output ./parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/weights/snowbridge_pallet_ethereum_client.rs
+popd