add project as category to back-end

Author: maryhipp

invokeai/app/services/workflow_records/workflow_records_common.py

@@ -31,6 +31,7 @@ class WorkflowRecordOrderBy(str, Enum, metaclass=MetaEnum):
 class WorkflowCategory(str, Enum, metaclass=MetaEnum):
     User = "user"
     Default = "default"
+    Project = "project"
 
 
 class WorkflowMeta(BaseModel):