A&E Phase II dynamic action serialization/deserialization

[streamich]

As part of Actions & Embeddables Phase II API we will need to persist dynamic actions created by user. For that we need ability to serialize an action to POJO and re-create it back from the serialized object.

• Serialize action.
• Deserialize action.

Parent issue: #43299

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)