Add option to exclude test key stats on platform admin page

This page currently includes all notifications for all services, including
those sent using a test key. Stats on all other pages exclude test key usage,
though, which can lead to confusion for admins comparing numbers between
pages. Adding the option to toggle between including and excluding test key
usage on the platform admin page gives context for this difference, and allows
admins to see live usage of the platform as well as load associated with test
key usage.

app/main/views/platform_admin.py

@@ -1,6 +1,9 @@
 import itertools
 
-from flask import render_template
+from flask import (
+    render_template,
+    request
+)
 from flask_login import login_required
 
 from app import service_api_client
@@ -13,10 +16,15 @@ from app.statistics_utils import get_formatted_percentage
 @login_required
 @user_has_permissions(admin_override=True)
 def platform_admin():
+    include_from_test_key = request.args.get('include_from_test_key') != 'False'
     # specifically DO get inactive services
-    services = service_api_client.get_services({'detailed': True})['data']
+    api_args = {'detailed': True}
+    if not include_from_test_key:
+        api_args['include_from_test_key'] = False
+    services = service_api_client.get_services(api_args)['data']
     return render_template(
         'views/platform-admin.html',
+        include_from_test_key=include_from_test_key,
         **get_statistics(sorted(
             services,
             key=lambda service: (service['active'], service['created_at']),