Add XCM integration tests

[shaunxw]

We currently have xcm-simulator-tests, which is not ideal as it's based on a mock runtime duplicating Shiden runtime. Instead, all runtimes including Shibuya/Shiden/Astar should be covered and the tests should be done against real-life relay chain and parachain runtimes.

There are 2 options for us:

1. Chopsticks
   • Pros: test on live network forks, is able to cover more scenarios like HRMP channels, between runtimes with different XCM/deps version.
   • Cons: tests are written with TS/JS.
2. XCM emulator
   • Pros: written in Rust.
   • Cons: cannot test HRMP channels; runtimes need to be the same deps version; will introduce extra build overhead for tests, CI.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[Dinonard]

Emulator added via this uplift: #978

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[ermalkaleci]

@Dinonard @shaunxw I believe this is already solved

[Dinonard]

True!