Add link to Prometheus UI in alert description

- extract from generatorURL field
- add ALERTS{alertname="<name>",alertstate="firing"} query
- unify alert subject format with email and slack

Change-Id: Ic16e09552dc447861dc552f60c9e313234dadd00
Related-PROD: PRODX-7212
diff --git a/sf_notifier/settings/development.py b/sf_notifier/settings/development.py
index 08607ac..06d3065 100644
--- a/sf_notifier/settings/development.py
+++ b/sf_notifier/settings/development.py
@@ -1,3 +1,5 @@
+import os
+
 VERSION = 'development'
 
 LOGGING = {
@@ -27,4 +29,7 @@
     'CONFIGURE_LOGGING': True,
 }
 
+ADD_LINKS = os.environ.get('SF_NOTIFIER_ADD_LINKS',
+                           False) in ['true', 'True', True]
+
 SF_CONFIG = {}