Count of orgs and live services for platform admin

This makes it consistent that an option which contains more options has
a hint about how many options it contains.

Also adds a formatter to get us ready for 1,000 services 🎉

app/main/views/choose_account.py

@@ -1,7 +1,9 @@
 from flask import redirect, render_template, session, url_for
 from flask_login import current_user
 
+from app import status_api_client
 from app.main import main
+from app.models.organisation import Organisations
 from app.utils import PermanentRedirect, user_is_logged_in
 
 
@@ -18,9 +20,17 @@ def services_or_dashboard():
 @main.route("/accounts")
 @user_is_logged_in
 def choose_account():
+    org_count, live_service_count = None, None
+    if current_user.platform_admin:
+        org_count, live_service_count = (
+            len(Organisations()),
+            status_api_client.get_count_of_live_services_and_organisations()['services'],
+        )
     return render_template(
         'views/choose-account.html',
         can_add_service=current_user.is_gov_user,
+        org_count=org_count,
+        live_service_count=live_service_count,
     )