[TASK] Improve BE performance by caching previews
[TASK] Clean up and unify template variable assignments in Preview etc.
[TASK] Clean up trigger condition and record load function
[BUGFIX] Label path generation for Form instances
[TASK] Return raw LLL prefixed description if translation fails
[TASK] Fix failing tests
[BUGFIX] Restore doubled variable in Preview section for legacy
[BUGFIX] Preview should render header/content in right place
Merge pull request #418 from NamelessCoder/previewcache

[TASK] Improve BE performance by caching previews