Only load plugins if PLUGINS_ENABLED is true

- Hide plugin settings
- Add plugin support status to "stats" dialog

InvenTree/part/templatetags/inventree_extras.py

@@ -7,6 +7,7 @@ over and above the built-in Django tags.
 
 import os
 import sys
+import django
 from django.utils.html import format_html
 
 from django.utils.translation import ugettext_lazy as _
@@ -107,6 +108,13 @@ def inventree_docker_mode(*args, **kwargs):
     return djangosettings.DOCKER
 
 
+@register.simple_tag()
+def plugins_enabled(*args, **kwargs):
+    """ Return True if plugins are enabled for the server instance """
+
+    return djangosettings.PLUGINS_ENABLED
+
+
 @register.simple_tag()
 def inventree_db_engine(*args, **kwargs):
     """ Return the InvenTree database backend e.g. 'postgresql' """