Add clarity on MTM environment that is being displayed

[Stan-vw]

Problem: it's not clear what version of the container is currently being shown: the live container, a draft version, or the preview version.

Context:

• we've received feedback that it's not clear which version is being shown when in the MTM section
• we've received feedback it's not clear that when a change is made, that this is not immediately published (i.e. when you make a change after publishing a version, you are now in a draft version but this is not explained in the product)
• we've received feedback that the preview mode overlay doesn't explain properly what is happening/can be done

Initial designs:
When no changes have been made since the current version is published:

When preview mode is enabled:

When there are any unsaved changed:

TBD:

• what environment/setting should be shown when looking at the latest version after publishing before any new changes, if that version was not used as the live environment (example: v4 in below screenshot)
  

• should the environment (live/staging/dev) be mentioned somewhere?