Document events being emitted for content flow actions

I would expect that long-running operations emit events in order to be notified upon completion or failure (otherwise one would need to rely on polling with https://developer.adobe.com/experience-cloud/cloud-manager/reference/api/#tag/ContentSets/operation/listContentFlows). Currently https://developer.adobe.com/experience-cloud/cloud-manager/reference/events/ only list the events for pipeline step operations.

首先查看 issue 中链接的 Cloud Manager 事件参考和 ContentSets listContentFlows 操作。记录为 content flow 操作发出的事件，并提供足够的详细信息，使用户无需 polling 即可监控其完成或失败。

由索引模型根据 Issue 内容生成。