Add is system flag to object metadata (#2481)

* Add isSystem flag to objectMetadata

* squash migrations and add dataSource->objects FK

* fix missing datasource enum type

server/src/metadata/object-metadata/dtos/object-metadata.dto.ts

@@ -53,6 +53,9 @@ export class ObjectMetadataDTO {
   @Field()
   isActive: boolean;
 
+  @Field()
+  isSystem: boolean;
+
   @HideField()
   workspaceId: string;