Feature request: Add asset-registry migration for XCMv4 multilocations

[wischli]

When this repository started supporting XCMv3 as part of the update to Polkadot v0.9.38 in #886, the storage version of the asset registry was bumped and a migration was added to migrate v2 locations to v3.

I was wondering whether there are any plans to do the same for XCMv4 which was introduced in Polkadot SDK v1.7.0.

[xlc]

There is no reason to migrate to v4, which is exactly the same as v3 other than version bump and rename. Best to wait for V5 and migrate to it instead.

[lemunozm]

To interact through the asset_registry traits (Inspect and Mutate), the API expects V4, but the orml_asset_registry implementation uses V3 under the hood. Do you know if all V4 locations can be internally translated to V3? Or should I expect i.e. that calling Inspect::metadata_by_location() can fail for some V4 Location?

[xlc]

the only thing changed is version number and otherwise 100% compatible

[lemunozm]

Thanks for the double-checking!

[wischli]

Closing due to the isometry between V3 and V4 xcm locations. Thanks for your answers @xlc!