Improve how we pass data when changing URLs

This commit adds a couple helpful features to make it easier for us to
reference routes, update URLs (both at development time and in the
    browser at runtime) and pass data between routes.

See the UI docs for the specifics on how these features work.

awx/ui/static/js/docs.js

@@ -1 +1,2 @@
 import 'tower/shared/multi-select-list/main.js';
+import 'tower/shared/route-extensions/main.js';