Update serializer for plugin settings API

- Use string key rather than pk for plugin
- Allow filtering by 'enabled' status of the plugin
- Allow filtering by the plugin key

InvenTree/plugin/api.py

@@ -12,6 +12,8 @@ from rest_framework import status
 from rest_framework import permissions
 from rest_framework.response import Response
 
+from django_filters.rest_framework import DjangoFilterBackend
+
 from common.api import GlobalSettingsPermissions
 from plugin.models import PluginConfig, PluginSetting
 import plugin.serializers as PluginSerializers
@@ -98,6 +100,15 @@ class PluginSettingList(generics.ListAPIView):
         GlobalSettingsPermissions,
     ]
 
+    filter_backends = [
+        DjangoFilterBackend,
+    ]
+
+    filter_fields = [
+        'plugin__active',
+        'plugin__key',
+    ]
+
 
 class PluginSettingDetail(generics.RetrieveUpdateAPIView):
     """

InvenTree/plugin/serializers.py

@@ -138,7 +138,7 @@ class PluginSettingSerializer(GenericReferencedSettingSerializer):
         'plugin',
     ]
 
-    plugin = serializers.PrimaryKeyRelatedField(read_only=True)
+    plugin = serializers.CharField(source='plugin.key', read_only=True)
 
 
 class NotificationUserSettingSerializer(GenericReferencedSettingSerializer):