🏷️(backend) accept string as saved document

Saved documents has to be a string now.
Before it has to be a json object.

src/backend/core/api/serializers.py

@@ -7,8 +7,6 @@ from timezone_field.rest_framework import TimeZoneSerializerField
 
 from core import models
 
-from .fields import JSONField
-
 
 class UserSerializer(serializers.ModelSerializer):
     """Serialize users."""
@@ -136,7 +134,7 @@ class BaseResourceSerializer(serializers.ModelSerializer):
 class DocumentSerializer(BaseResourceSerializer):
     """Serialize documents."""
 
-    content = JSONField(required=False)
+    content = serializers.CharField(required=False)
 
     class Meta:
         model = models.Document

src/backend/core/api/viewsets.py

@@ -344,7 +344,7 @@ class DocumentViewSet(
 
         return drf_response.Response(
             {
-                "content": json.loads(response["Body"].read()),
+                "content": response["Body"].read().decode("utf-8"),
                 "last_modified": response["LastModified"],
             }
         )