Improve view only mode

1. Hide all control buttons except run-all button in report mode.
2. Hide paragraph completely (no space for paragraph) when output is hidden.
3. Fix bug that hidden paragraph appears when running note.
4. For fixing 3, I needed to refactor some *BAD* part of the paragraph controller. 
It can be set using css if we set a ng-class in the notebook.

It's more of a code reading question, it looks better to have a value check at only one spot instead of 15, however it can be hard to find that one and only line that change the whole context, it might also in some case not possible to set everything using CSS.

we are already using asIframe in the same way inside of the paragraph.

If we decide to go into a css only solution, we need to apply the same thing with asIframe, and test both case well.

We can always make a PR to change the way it is set, and see later if we apply it or not