New design is bound to BrowserRootCategories collection

New design is bound to BrowserRootCategories collection. There are some bugs but we have something to show. Works correctly for Geometry category. Possible too long names of some functions. For example: `Geometry.Cuboid`.

@Benglin, please review.
```ClassObject``` and ```ClassDetails``` classes in the prototype was to show how we could use template selector, but here we might not want to introduce these ```BrowserClassElement``` and ```BrowserDetailsElement``` classes. See my comment on the main conversation for details.