add stats boxes to platform admin page

moved a couple of stats summary functions from dashboard to a shared statistics_utils file

app/main/views/platform_admin.py

@@ -1,8 +1,13 @@
+from datetime import datetime
+
+import pytz
 from flask import render_template
 from flask_login import login_required
 
+from app import statistics_api_client
 from app.main import main
 from app.utils import user_has_permissions
+from app.statistics_utils import sum_of_statistics, add_rates_to
 
 
 @main.route("/platform-admin")
@@ -10,5 +15,12 @@ from app.utils import user_has_permissions
 @user_has_permissions(admin_override=True)
 def platform_admin():
     return render_template(
-        'views/platform-admin.html'
+        'views/platform-admin.html',
+        global_stats=get_global_stats()
     )
+
+
+def get_global_stats():
+    day = datetime.now(tz=pytz.timezone('Europe/London')).date()
+    all_stats = statistics_api_client.get_statistics_for_all_services_for_day(day)['data']
+    return add_rates_to(sum_of_statistics(all_stats))