When a specific version of an experience page is rendered in the CM, it should be possible to restore that version of the experience page from the CM

Functional details

Only when the currently rendered version is a version for which the branchId still exists AND the rendered version (of the branch) should not be the LATEST version for that branch, otherwise restoring that version will result in nothing new.

There are two ways how the frontend can decide whether 'restore version' should be enabled. Options

1. The frontend compares the UUID of the html page comment containing 'HST-Unpublished-Variant-Id' with the list of available versions for the current branch: if the newest (the first) version in the list of available versions is equal to 'HST-Unpublished-Variant-Id', there is nothing to restore
2. The HST will provide in the html page comment next to 'HST-Unpublished-Variant-Id' also a boolean flag, something like 'HST-Rendered-PrimaryDocument-Restorable = true | false'

jdegooijer WDYT? Can you let me know your preference