Duplicating a dashboard widget should preserve its size/dimensions

## What?

Duplicating a dashboard can save time by not having to respecify things like search query, stream. However, the size and location of the newly created widget resets to the default size and position at top left of page.

It would be helpful and make editing dashboards more efficient if a duplicated widget could be placed next to the original, and the size/dimensions are also copied from the original onto the copied widget.

## Why?

Working on dashboards that have many widgets can be cumbersome and duplicating widgets requires a lot of scrolling and dragging.

## Your Environment

* Graylog Version: 5.0.1
* Operating System: Ubuntu Server 20.04 LTS
* Browser version: Chrome 108.0.5359.124