feat: add async XCM contract call scenario (#941)

* feat: remove fixtures dir

* feat: add utilty method to call contract method

* feat: build.rs for compiling ink! contracts

* fix: ci build issues

* feat: add async xcm ink! contract fixture

* feat: add async xcm experimental scenario

* feat: add call filter to allow `pallet_xcm:send` only

* docs: add comments

* fix: make clippy happy

* fix: make clippy happy again

* feat: apply review suggestions

* lint: make clippy happy

* feat: update package meta for fixture contracts

* feat: move `contract-build` dep to workspace

* feat: automatically pick contracts from contarcts_dir

* refactor: move build contracts method to `BuildConfig`

* docs: update readme for contract fixtures

* feat: remove build script for contract compilation

* feat: revert build script changes

tests/xcm-simulator/Cargo.toml

@@ -92,5 +92,6 @@ runtime-benchmarks = [
 	"xcm-executor/runtime-benchmarks",
 	"polkadot-runtime-parachains/runtime-benchmarks",
 	"polkadot-parachain/runtime-benchmarks",
+	"orml-xtokens/runtime-benchmarks",
 	"astar-primitives/runtime-benchmarks",
 ]

tests/xcm-simulator/fixtures/README.md

@@ -4,3 +4,4 @@ This directory contains contracts which are used in experimental scenarios.
 Files in this directory are used by experimental scenarios in `src/experimental.rs`. The json
 files are for informational purposes only and are not consumed by the tests.
 
+The source code for the contracts can be found at https://github.com/AstarNetwork/ink-test-contracts