Implement Horizon UI patterns

On the app catalog index, remove the right-side control bar (search,
category, env) and replace with more "Horizon"-like UI elements at the
top of the page. Rename "Latest Apps" to "Recent Activity" and add info
text if no results. Add search query term to search field when showing
search results (UX).

Change-Id: I224dcd1946e846f198b909dd3020df2c09ec615b
Implements: blueprint murano-ui-horizon-patterns