Move asset owners list into a separate service

[qubicmio]

What, why, who?

The users of the explorer (explorer.qubic.org) would like to see asset ownership information of top holders ordered by number of shares because they would like to see how much others own and where their own holdings are in relation to others.

Additional information

Currently this information is available in the QX service for QX transactions. But asset transfers are more general than QX and not directly related to it. Therefore it should be moved into an own service that can accessed by the explorer and considers all asset transfers.

Accepance criteria

• Functionality as in the current implementation (API, limits, import).
• Update ownership information on every ownership change events and asset issuance events.

Out of scope

• Reimplementation in go (can be done in a further issue, if needed).

Technical sketch

• Move current code into own service.
• Keep db and caching as is.
• Replace ingestion mechanism (listen for all events).
• Remove asset owners from qx-service.

Open issues

• Hosting

Related issues

See issues #5, qubic/explorer-frontend#208

[qubicmio]

Moved into new service. Dev test url https://qxinfo.org/aos/api.

For example: https://qxinfo.qubic.org/aos/api/v1/issuers/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAFXIB/assets/QX/owners