Clone region copies API token

[svenseeberg]

Describe the Bug

When a region is cloned the access token for the push page content API endpoint is cloned as well. This is a leak of information as users of the newly cloned region can use this token to push content to the source region.

Steps to Reproduce

1. Edit a page and set the "API access token"
2. Clone the region
3. Open the page in the cloned region and look at the token.

Expected Behavior

API access tokens should be cleared after cloning.

Actual Behavior

API access tokens are cloned along all other page properties.

Additional Information

Should we reserve a CVE? 😹