Since https://github.com/discourse/discourse/commit/a440e15, we have started to support objects typed theme setting so we are switching this theme component to use it instead as it provides a much better UX for configuring the settings required for the theme component.
This commits introduces the follow changes:
1. Use the `renderInOutlet` API over the connectors convention
1. Renames `discourse-category-banners` component to `category-banner`
which is more appropriate cause we are only rendering banner for one
category.
1. Adds system tests
David Taylor
overgrow
Alan Guo Xiang Tan
Jarek Radosz
Kris