Add aliasers to westend chains (#6814)
`InitiateTransfer`, the new instruction introduced in XCMv5, allows
preserving the origin after a cross-chain transfer via the usage of the
`AliasOrigin` instruction. The receiving chain needs to be configured to
allow such this instruction to have its intended effect and not just
throw an error.
In this PR, I add the alias rules specified in the [RFC for origin
preservation](https://github.com/polkadot-fellows/RFCs/blob/main/text/0122-alias-origin-on-asset-transfers.md)
to westend chains so we can test these scenarios in the testnet.
The new scenarios include:
- Sending a cross-chain transfer from one system chain to another and
doing a Transact on the same message (1 hop)
- Sending a reserve asset transfer from one chain to another going
through asset hub and doing Transact on the same message (2 hops)
The updated chains are:
- Relay: added `AliasChildLocation`
- Collectives: added `AliasChildLocation` and
`AliasOriginRootUsingFilter<AssetHubLocation, Everything>`
- People: added `AliasChildLocation` and
`AliasOriginRootUsingFilter<AssetHubLocation, Everything>`
- Coretime: added `AliasChildLocation` and
`AliasOriginRootUsingFilter<AssetHubLocation, Everything>`
AssetHub already has `AliasChildLocation` and doesn't need the other
config item.
BridgeHub is not intended to be used by end users so I didn't add any
config item.
Only added `AliasChildOrigin` to the relay since we intend for it to be
used less.
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Co-authored-by: GitHub Action <[email protected]>
Co-authored-by: command-bot <>