Support for Foreign Assets on Assets Hub chains (Statemine / Statemint)

[IkerAlus]

Proposed Feature

Statemine runtime v9420 and (most likely) Statemint runtime v9430 will have support for foreign fungible assets. This will allow other parachains to represent their assets, as well as bridges to represent assets from other networks. Hence external teams with an integration with Assets Hub chains, particularly exchanges, will be interested in querying the foreign asset information from the chain. That is why API Sidecar should allow to query such information.

This feature is realized by the addition of a new pallet, foreignAssets, to these runtimes. This new pallet has the same interface than the well-known assets pallet, thus a good approach may be to add similar endpoints to API Sidecar to query the storage of this new pallet. Following the current endpoints for assets pallet this could be:

• GET /accounts/{accountID}/asset-balances
• GET /accounts/{accountID}/asset-approvals
• GET /pallets/assets/{assetID}/asset-info

Additional Information

Check the respective PRs for Statemine and Statemint to learn the details of the feature.

[IkerAlus]

partially done in https://github.com/paritytech/substrate-api-sidecar/pull/1314

Closing this for now and reconsidering the remaining functionality in the future.