Adds keyboard shortcut for refreshing all feeds

- Binds the 'R' key to trigger a refresh in the background for all
feeds.
- Updates the locale, using the same description as the link in the
feeds page.

Co-authored-by: Vitor Pellegrino <pellegrino@linux.com>

ui/static/js/request_builder.js

@@ -14,6 +14,11 @@ class RequestBuilder {
         };
     }
 
+    withHttpMethod(method) {
+        this.options.method = method;
+        return this;
+    }
+
     withBody(body) {
         this.options.body = JSON.stringify(body);
         return this;