Metadata workflow - enabling the workflow in a metadata published should set the status as approved

**Describe the bug**
When enabling the metadata workflow in a metadata that is published and was created before the workflow was enabled in the system, the metadata status is set to `Draft`. This is a bit inconsistent as the metadata is public. I think in this case should be set the status as `Approved`.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a metadata with the workflow not activated.
2. Publish the metadata.
3. Activate the workflow.
4. Enable the workflow in the metadata --> the metadata is set to draft status and remains published.

**Expected behavior**
As the metadata is already published, the metadata status should be set as `Approved`.

Reproduce the issue using the four steps in the report, then trace the metadata workflow enable operation and its status assignment. Done means enabling the workflow on an already published metadata leaves it published and sets its status to Approved.

Written by the indexing model from the issue text.