Nebular Window Controls

### Issue type

**I'm submitting a ...** (check one with "x")

* [ ] bug report
* [x] feature request

### Issue description
Hi! Working so far with this library has been wonderful. And I just wanted to ask if it is possible to have an update in the future over the control of nebular window. Here are some features, I'd wish to see at one point if at all possible.

#### Draggable
A useful tool, that would give a user the ability to interact with the window which can lead them to compare and contrast between different windows. As well as interact with the content of the web application.
CDK drag and drop is a tool, I've used thus far to get such a feature possible.

#### Drag & Drop (snap to grid)
Full screen drag and drop (snapping) could occur the same way how applications are handled in windows OS. As an example, the user could place the window at a location of their own will, and still be able to have access to different things. This would also mean that they'd have control over how much they want to see which leads me to..

#### Resize
Would be nice to give the user control over how much of the window they'd wish to see..