When a user browses the discussion pages, show a page showing
that there is no data, rather than a blank page.
This PR implements the designs for this page while refactoring the
DiscussionHome component so that it doesn't get much larger.
- Created a hooks file and move some of the larger hooks in there.
- Added selectors for the state that would be needed for the
components.
- Split the DiscussionHome into DiscussionContent and
DiscussionSidebar to make it clearer where certain things get
rendered.
- Adds a message to the sidebar to display No Results when
appropriate.
- Added the NoResults component to show when filtering posts and there
is nothing to show.
