Workflow-specific string/regex pre-filtering for Drop-down Menus

### Feature Idea

### Problem:
As the ecosystem of specialized models grows (Flux, LTX-Video, Wan, Qwen-Edit, etc.), the checkpoints, diffusion_models, lora, and text_encoder directories have become incredibly bloated. When working in a highly specialized workflow (e.g., a Qwen-Edit pipeline), clicking the "Load Diffusion Model" node brings up a drop-down list of 50+ completely irrelevant models. In workflows where there are several different models with various strengths and weaknesses, it would be a huge QoL improvement not to have to scroll or manually type a search query every single time I need to swap a model within a specific workflow.

### Solution:
I would like the ability to assign a pre-filter (via string matching, regex, or subfolder target) to the properties of a specific drop-down node within a workflow.

For example, right-clicking the "Load Diffusion Model" node could reveal a Set Dropdown Filter option. If I type *qwen* or Qwen_Subfolder/ into that filter, the node saves that parameter to the workflow JSON. From then on, clicking that specific node's drop-down will only populate with the 2 or 3 models that match the filter, hiding the rest of the directory.

### Existing Solutions

1. Subfolder Search: Organizing models into subfolders and typing the subfolder name into the drop-down every time I open it. (Still requires manual typing/searching upon every interaction).
3. Custom Nodes: Converting the unet_name to an input and using third-party string/list nodes to feed the specific filenames into the loader. (Clunky, adds unnecessary node-spaghetti to the workflow, and relies on third-party maintenance).

### Other

_No response_