[Asset Discovery] Account is not being published as an entity

Apart from `GCP Project` ([here](https://github.com/elastic/cloudbeat/blob/main/internal/inventory/asset.go#L128)) Asset Discovery is not publishing AWS and Azure accounts as an stand alone entity, when it should.

- In a single account deployment, we need to publish the single account.
- In an organization deployment, we need to publish all scanned acounts