Allow excluding services from live services count

Adds a front end for:
https://github.com/alphagov/notifications-api/pull/2417

> Sometimes we have to make a few services for what really is one
> service, for example GOV.UK Pay and GOV.UK Pay Direct Debit. We also
> have our own test services which aren’t included in the count of live
> services. We currently count these as one service by not including
> them in the beta partners spreadsheet.

app/navigation.py

@@ -261,6 +261,7 @@ class HeaderNavigation(Navigation):
         'service_settings',
         'service_sms_senders',
         'service_switch_can_upload_document',
+        'service_switch_count_as_live',
         'service_switch_live',
         'service_set_permission',
         'services_or_dashboard',
@@ -506,6 +507,7 @@ class MainNavigation(Navigation):
         'service_delete_sms_sender',
         'service_letter_validation_preview',
         'service_switch_can_upload_document',
+        'service_switch_count_as_live',
         'service_switch_live',
         'service_set_permission',
         'services_or_dashboard',
@@ -749,6 +751,7 @@ class CaseworkNavigation(Navigation):
         'service_settings',
         'service_sms_senders',
         'service_switch_can_upload_document',
+        'service_switch_count_as_live',
         'service_switch_live',
         'service_set_permission',
         'services_or_dashboard',
@@ -999,6 +1002,7 @@ class OrgNavigation(Navigation):
         'service_settings',
         'service_sms_senders',
         'service_switch_can_upload_document',
+        'service_switch_count_as_live',
         'service_switch_live',
         'service_set_permission',
         'services_or_dashboard',