[Beats] Enhancement to add support for string type of events.

[piyush-elastic]

We are planning to create an integration for Bitwarden and using different APIs provided by Bitwarden. We have encountered with an endpoint where we are getting a response in below format:

[
"3fa85f64-5717-4562-b3fc-2c963f66afa6"
]

When we configured same endpoint in Beats, we observed that in debug log we are getting below error message:

events must be JSON objects, but got string: skipping

We have also looked into response.go file and observed that it is not able to convert input response to JSON object.

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[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!