Adjust asset lookup paths when chat is enabled

When chat is enabled, we need to add the Jabber Django app's static
asset and template directories to the corresponding lookup paths.

lms/envs/aws.py

@@ -147,6 +147,11 @@ for app in ENV_TOKENS.get('ADDL_INSTALLED_APPS', []):
 for feature, value in ENV_TOKENS.get('MITX_FEATURES', {}).items():
     MITX_FEATURES[feature] = value
 
+# Chat
+if MITX_FEATURES.get("ENABLE_CHAT"):
+    MAKO_TEMPLATES['main'].append(PROJECT_ROOT / 'djangoapps' / 'jabber' / 'templates')
+    STATICFILES_DIRS.append(PROJECT_ROOT / 'djangoapps' / 'jabber' / 'static')
+
 WIKI_ENABLED = ENV_TOKENS.get('WIKI_ENABLED', WIKI_ENABLED)
 local_loglevel = ENV_TOKENS.get('LOCAL_LOGLEVEL', 'INFO')