Attack Discovery API

**What the feature is**: Attack Discovery API

**Value proposition**: Attack Discovery can now be triggered programmatically, via any automation platform or tooling that users wish. This API also includes the ability to update workflow state, sharing options, and much more, giving users the freedom to automate any of this functionality.

**Expected outcome**: Whilst users enjoy leveraging Attack Discovery within Kibana, many of our customers want to be able to use it within automation and SOAR workflows, just like they currently do with traditional alerts. This feature enables them to do that, and also aligns with the rest of our features, which all have an APIs.

**Optional: Key user stories / use cases**