Add entities.metadata

[romulets]

Summary of your changes

As part of implementing the first iteration of the Cloud Entities in Entity Store, we need to populate the field entities.metadata with the relevant information

Screenshot/Data

Related Issues

• Related https://github.com/elastic/security-team/issues/11094
• Related https://github.com/elastic/security-team/issues/10961

[mergify]

This pull request does not have a backport label. Could you fix it @romulets? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
  NOTE: backport-v8.x has been added to help with the transition to the new branch 8.x.

[kubasobon]

The code looks good. Asking a couple of questions for my information. We can catch-up on Zoom about this if you'd like that better.

[kubasobon]

That's super important. We also have to pay attention to always put "the" asset ID in the ids[0] spot.

[romulets]

This is a product question I want to clear it up. I believe it was a bad decision in the end to have multiple ids.

We need to have a standardized id per resource. We need to make the decision for example is aws iam user arn or username? And one for each one of those.

The initial attempt of having a "correlation best chance" approach isn't going to help us in the asset inventory, unfortunately.

[kubasobon]

Are there any other fields planned? What will happen if we change the taxonomy we have now (Category, Sub-Category, Type, Sub-type) to a less granular one?

[romulets]

There might have other fields.

Once we change the taxonomy, we should follow the taxonomy.