feat: display all child tags in the "bare bones" taxonomy detail page (#703)

Also includes:
- feat: set <title> on taxonomy list page and taxonomy detail page
- fix: display all taxonomies on the list page, even if > 10
- refactor: separate out loading spinner component

src/taxonomy/data/api.js

@@ -7,6 +7,7 @@ const getApiBaseUrl = () => getConfig().STUDIO_BASE_URL;
 export const getTaxonomyListApiUrl = (org) => {
   const url = new URL('api/content_tagging/v1/taxonomies/', getApiBaseUrl());
   url.searchParams.append('enabled', 'true');
+  url.searchParams.append('page_size', '500'); // For the tagging MVP, we don't paginate the taxonomy list
   if (org !== undefined) {
     url.searchParams.append('org', org);
   }