Add SUPIR Upscaler

### Model/Pipeline/Scheduler description

[SUPIR](https://supir.xpixel.group/) is a super-resolution model that looks like it produces excellent results

Github Repo: https://github.com/Fanghua-Yu/SUPIR

The model is quite memory intensive, so the optimisation features available in diffusers might be quite helpful in making this accessible to lower resource GPUs.

### Open source status

- [X] The model implementation is available.
- [X] The model weights are available (Only relevant if addition is not a scheduler).

### Provide useful links for the implementation

_No response_

Start by reading the SUPIR project and implementation repository linked in the issue, then review how diffusers exposes model and pipeline integrations. Clarify the integration scope, including how the available optimization features should address SUPIR's memory requirements; done means the model is supported in diffusers with appropriate validation.

Scritto dal modello di indicizzazione a partire dal testo della issue.