exp: create table copy/paste functionality

[scottdover]

This is just a very rough proof of concept. Since we don't/can't support the enterprise of AG grid, we don't have out of the box support for copy/paste. Thus, the aims to put together a couple of things to support copy paste:

• A selection rectangle that's "drawn" when holding down shift and dragging
• The ability to copy/paste all cells under the rectangle using cmd/ctrl + c

Here's a quick demo of how things look from a UI perspective:

Here are some things to think about when moving forward with a more full-featured solution:

• When drawing a rectangle, you should be able to draw it from any corner. At the moment, we only support drawing left,top -> right,bottom
• We should probably have a menu or buttons or something to provide the functionality to copy with or without formatting
• At the moment, this has not been tested with scrolling at all. A more complete solution should test wide data and should likely include the ability for drag to scroll the table.