fix(moderator): as a creator of the test I can not enter inside preview

[marcgc21]

[tejasveersmatharu-debug]

@marcgc21 Can I work on this issue, if someone else isn't?
Before I start — should the preview button be disabled for creator (which shows message on hover),
or should the creator be let into the preview page fully (with the heuristics section showing an empty/add-heuristics state),
or should they see a different screen than the current hard block, but still not enter?