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/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_ethereum_beacon_client \
+--extrinsic="*" \
+--execution=wasm --wasm-execution=compiled \
+--steps 50 --repeat 20 \
+--output ./parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/weights/snowbridge_ethereum_beacon_client.rs
+popd