* Component: GridContentControl for controlling visibility of product content
* Add the content control to all grid blocks
* Use CSS to hide the content on the front end
* Fix missing translation functions
* Add a new LayoutControl component
* Use new LayoutControl to handle rows & columns settings
* Fix errors when rows or columns is empty (silently fall back to default to prevent breaking the block)
* Rename `LayoutControl` to `GridLayoutControl`
This lets us use the functionality of `register_block_type` to automatically enqueue the scripts and styles used by blocks in the editor, and eventually, styles on the frontend as well. Also adds cssnano to minify our CSS.
Kelly Dwan
Timmy Crawford