Add collectives-westend and glutton-westend runtimes (#2024)

Add collectives and glutton parachain westend runtimes to prepare for
#1737.

The removal of system parachain native runtimes #1737 is blocked until
chainspecs and runtime APIs can be dealt with cleanly (merge of #1256
and follow up PRs).

In the meantime, these additions are ready to be merged to `master`, so
I have separated them out into this PR.

Also marked `bridge-hub-westend` as unimplemented in line with [this
issue](https://github.com/paritytech/parity-bridges-common/issues/2602).

TODO
- [x] add to `command-bot` benchmarks
- [x] add to `command-bot-scripts` benchmarks
- [x] generate weights

---------

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Muharem <ismailov.m.h@gmail.com>
Co-authored-by: command-bot <>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>

cumulus/parachains/runtimes/collectives/collectives-westend/build.rs

@@ -0,0 +1,26 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[cfg(feature = "std")]
+fn main() {
+	substrate_wasm_builder::WasmBuilder::new()
+		.with_current_project()
+		.export_heap_base()
+		.import_memory()
+		.build()
+}
+
+#[cfg(not(feature = "std"))]
+fn main() {}