Add All Original Messages To event.original ECS Field

[UcanInfosec]

Describe the enhancement:
Add code in modules to Add All Original Messages To event.original ECS Field

Describe a specific use case for the enhancement or feature:
This would allow for future use of the original message. And some events have the message field. Would also allow future parsing or work as original message is preserved.

[botelastic]

This issue doesn't have a Team:<team> label.

[botelastic]

Hi!
We just realized that we haven't looked into this issue in a while. We're sorry!

We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1.
Thank you for your contribution!