Rococo/Westend Coretime Runtime

New runtimes for the Coretime Chain (a.k.a. "Broker Chain") described in
RFC-1.

Replaces https://github.com/paritytech/cumulus/pull/2889


- [x] Add Agile Coretime pallet
https://github.com/paritytech/substrate/pull/14568
- [x] Generate chain specs for local and testnets
- [x] Deploy parachain on Rococo - Done:
[rococo-coretime-rpc.polkadot.io](https://polkadot.js.org/apps/?rpc=wss%3A%2F%2Frococo-coretime-rpc.polkadot.io#/explorer)

DevOps issue for Aura keygen:
https://github.com/paritytech/devops/issues/2725

Edit (Dónal): This PR is mainly for Rococo, the Westend runtime is a
shell with no `Broker` pallet. The Rococo runtime has the broker calls
filtered for initial deployment.

---------

Co-authored-by: Dónal Murray <donal.murray@parity.io>
Co-authored-by: 0xmovses <r.v.melkonian@gmail.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Marcin S. <marcin@realemail.net>
Co-authored-by: Bastian Köcher <info@kchr.de>
Co-authored-by: command-bot <>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>

.gitlab/pipeline/check.yml

@@ -223,6 +223,19 @@ check-runtime-migration-collectives-westend:
     URI: "wss://westend-collectives-rpc.polkadot.io:443"
     COMMAND_EXTRA_ARGS: "--disable-spec-name-check"
 
+# Check runtime migrations for Parity managed coretime chain
+check-runtime-migration-coretime-rococo:
+  stage: check
+  extends:
+    - .docker-env
+    - .test-pr-refs
+    - .check-runtime-migration
+  variables:
+    NETWORK: "coretime-rococo"
+    PACKAGE: "coretime-rococo-runtime"
+    WASM: "coretime_rococo_runtime.compact.compressed.wasm"
+    URI: "wss://rococo-coretime-rpc.polkadot.io:443"
+
 find-fail-ci-phrase:
   stage: check
   variables: