Add broker pallet to coretime-westend (#3272)

This brings functionality to Westend's Coretime Chain runtime, where
previously it was not much more than a shell.

It is assumed that the Coretime pallet will have the same index in the
Westend runtime as it does in Rococo for the runtime calls.

TODO:
- [x] Generate chainspec
- [x] Regenerate weights
- [x] Check hardcoded RuntimeCall weights against relay weights for
transacts

Aura key generation: https://github.com/paritytech/devops/issues/2725

---------

Co-authored-by: command-bot <>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Anton Vilhelm Ásgeirsson <antonva@users.noreply.github.com>

Cargo.lock

@@ -3110,7 +3110,6 @@ dependencies = [
  "pallet-xcm-benchmarks",
  "parachains-common",
  "parity-scale-codec",
- "polkadot-core-primitives",
  "polkadot-parachain-primitives",
  "polkadot-runtime-common",
  "rococo-runtime-constants",
@@ -3161,11 +3160,11 @@ dependencies = [
  "pallet-aura",
  "pallet-authorship",
  "pallet-balances",
+ "pallet-broker",
  "pallet-collator-selection",
  "pallet-message-queue",
  "pallet-multisig",
  "pallet-session",
- "pallet-sudo",
  "pallet-timestamp",
  "pallet-transaction-payment",
  "pallet-transaction-payment-rpc-runtime-api",
@@ -3174,7 +3173,6 @@ dependencies = [
  "pallet-xcm-benchmarks",
  "parachains-common",
  "parity-scale-codec",
- "polkadot-core-primitives",
  "polkadot-parachain-primitives",
  "polkadot-runtime-common",
  "scale-info",