_supportedLayout not working

[danielstorey]

I was trying to restrict a new component to full width only and it wasn't working. I couldn't figure out why until I started to dig into the code.

https://github.com/adaptlearning/adapt_authoring/blob/master/frontend/src/core/editor/page/views/editorComponentListView.js#L82-L83

The string representations of the keys should not have a "." and L83 should not have a hasOwnProperty call as it is the value itself we are trying to return.

I will try and PR when I get a chance