Fix design comment checkbox regression

What does this MR do?

1. Reverts changes from !33587 (diffs) as they caused a regression: now if form is empty, clicking a checkbox closes the form.
2. Implemented different logic for having only one form open

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers