Preview: Panel isn't displayed if it is collapsed and doesn't have a title

[RomanTsukanov]

Steps to reproduce:

1. Open Survey Creator
2. Add a panel to the design surface.
3. Add a question to that panel.
4. Select the panel, go to Layout, and set State to "collapsed".
5. Switch to the Preview tab.

Current UI:

Proposed UI:

[RomanTsukanov]

Panel dynamic also doesn't allow expanding/collapsing inner panels if the don't have a title template. It looks like these two issues are one and the same.