* Implement collapsing component hierarchy.
* Save screen when adding new components.
* Allow creation of nested child components.
* Rename updateComponentProps to setComponentProps
* Compile layout and position properties to css strings.
* Correct ordering errors.
* Compile the css for an entire screen.
* Add unique id for each component.
* Ignore _id props.
* Update client to add correct class names to component elements.
* Add grid-template fields to layout styling panel.
* Inject css into iframe. Minor tweaks.
* Fix unset margins.
* Update failing tests.
