Currently, the Landing Page Editor doesn't warn the Editor that another draft exists. It just lets the Editor edit the current published version without any warning or indication. Instead, the Editor should be presented with "Select a draft" modal like it is done when the Editor edits any other Content Type.

Steps to reproduce

1. Create new Ez Platform EE installation.
2. In the Platform UI, go to "Page".
3. Click "Edit" for the "Home" Content Object.
4. Make any change and save the draft without publishing it.
5. Leave the edit mode.
6. Click "Edit" again. You will be able to edit the published version again without any warning despite the fact that another draft exists.