Add Getty images as data source

## Problem
The Getty Images API ([API Documentation](https://developers.gettyimages.com/docs/)) provides access to a vast global library of premium visual content (images, illustrations, video, editorial) from Getty Images and iStock. The Getty Images API is currently at version 3 and it provides access to over 477 million assets. It exposes metadata on usage restrictions, license model, product types, see more at ([Meta data](https://developers.gettyimages.com/asset-metadata/)).

## API Information
- The Getty Images API requires all requests to include an Api Key to authenticate the client(in some cases require authorization)
- Uses the Base URL (v3): https://api.gettyimages.com/v3/
- Data is returned in JSON format.
- The Getty Images API throttles client requests based on limits associated with the client’s API Key. The rate limit is configured when a customer is initially setup to use the API

## Implementation

- [ ] I would be interested in implementing this feature.

Das Issue nennt keine Repository-Dateien oder Tests. Beginne damit, die vorhandenen Einstiegspunkte für Datenquellen mit der Dokumentation der Getty Images API v3 zu vergleichen, und berücksichtige anschließend die Authentifizierung per API-Key, JSON-Antworten und Rate-Limits; fertig bedeutet, dass Getty Images als Datenquelle verfügbar ist.

Vom Indexierungsmodell aus dem Issue-Text verfasst.