[common][serializers] Move from JSONSerializerField to standard JSONField

And normalize custom fields imports/use.

beat/web/common/serializers.py

@@ -44,7 +44,8 @@ from ..common.utils import validate_restructuredtext
 
 from .models import Shareable, Versionable, Contribution
 from .exceptions import ContributionCreationError
-from .fields import JSONSerializerField, StringListField
+
+from . import fields as serializer_fields
 
 
 # ----------------------------------------------------------
@@ -85,8 +86,8 @@ class CheckNameSerializer(serializers.Serializer):
 
 
 class SharingSerializer(serializers.Serializer):
-    users = StringListField(required=False)
-    teams = StringListField(required=False)
+    users = serializer_fields.StringListField(required=False)
+    teams = serializer_fields.StringListField(required=False)
 
     def validate_users(self, users):
         user_accounts = User.objects.filter(username__in=users).values_list(
@@ -300,7 +301,7 @@ class ContributionSerializer(VersionableSerializer):
 
 
 class ContributionModSerializer(serializers.ModelSerializer):
-    declaration = JSONSerializerField(required=False)
+    declaration = serializers.JSONField(required=False)
     description = serializers.CharField(required=False, allow_blank=True)
 
     class Meta: