edit subspace model to fix keys and integrate with backend

lib/pages/spaces_management/all_spaces/model/subspace_model.dart

@@ -27,7 +27,7 @@ class SubspaceModel {
       subspaceName: json['subspaceName'] ?? '',
       disabled: json['disabled'] ?? false,
       internalId: internalId,
-      tags: (json['tags'] as List<dynamic>?)
+      tags: (json['productAllocations'] as List<dynamic>?)
               ?.map((item) => Tag.fromJson(item))
               .toList() ??
           [],
@@ -36,7 +36,7 @@ class SubspaceModel {
 
   Map<String, dynamic> toJson() {
     return {
-      'uuid': uuid,
+      if (uuid != null) 'uuid': uuid,
       'subspaceName': subspaceName,
       'disabled': disabled,
       'tags': tags?.map((e) => e.toJson()).toList() ?? [],