Add status labels to portfolio managers table.

Update PortfolioRole.display_status() to return same type of data as
ApplicationRole.display_status().

templates/portfolios/admin.html

@@ -1,5 +1,6 @@
 {% extends "portfolios/base.html" %}
 
+{% from "components/label.html" import Label %}
 {% from "components/pagination.html" import Pagination %}
 {% from 'components/save_button.html' import SaveButton %}
 {% from 'components/sticky_cta.html' import StickyCTA %}