[Feature Request]: LoraLoader: option to autodetect filepaths from filenames

### Is there an existing issue for this?

- [x] I have searched the existing issues and checked the recent builds/commits

### What would your feature do ?

Currently the comfy json data saves the FULL paths of all models, and all the CheckpointLoaders, LoraLoaders, VAELoaders, UpscaleModelLoaders expect these paths to be working without exception. This leads to headaches when attempting to import image generations that originate from different webuis (like a1111/forge) and from other people with different path structures, requiring the user to ALWAYS re-set the filepaths.

Ie. there's no filename/filepath autodetection whatsoever for none of the strings like `ckpt_name`, `vae_name`, `model_name`, `lora_name`.

Below imported image had A1111 metadata which only contains the filenames.


I have over 2,000 loras which makes manually re-setting all the model data from the drop down menus extremely annoying when trying to recreate my old gens I've done on different webuis.

### Proposed workflow

1. Load a generated image with non-comfyui metadata
2. `lora_name(s)` appear without paths
4. Either press "Fix filepath" / "Auto-detect filepath" or have "Automatically detect filepaths" setting enabled
5. (save LOTS of time from re-setting file paths)

### Additional information

Preferably this feature would also be able to parse filenames from comfyuis full paths, making the metadata compatible between different comfyui users.

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-2395-Feature-Request-LoraLoader-option-to-autodetect-filepaths-from-filenames-18e6d73d365081d4b32ff4218c325995) by [Unito](https://www.unito.io)

Start by locating the CheckpointLoaders, LoraLoaders, VAELoaders, and UpscaleModelLoaders entry points and the handling of ckpt_name, vae_name, model_name, and lora_name. Trace how imported image metadata populates those values. Done means filenames from non-ComfyUI metadata and full ComfyUI paths can be resolved or manually fixed through the proposed workflow.

Written by the indexing model from the issue text.