Enhance workflow parsing and node mapper registration

- Introduced a new WorkflowParser class to streamline workflow parsing and manage node mappers.
- Added functionality to load external mappers dynamically from a specified directory.
- Refactored LoraLoaderMapper and LoraStackerMapper to handle new data formats for loras and trigger words.
- Updated recipe routes to utilize the new WorkflowParser for parsing workflows.
- Made adjustments to the flux_prompt.json to reflect changes in active states and class types.

py/workflow/ext/__init__.py

@@ -0,0 +1,3 @@
+"""
+Extension directory for custom node mappers
+"""