[Feature] Add User history

This PR adds a _User History_ feature:
- **Past generations** are saved and accessible in a separate section. Users can see all the images they've already generated.
- **metadata** are saved for each image (prompt, pipeline, timestamp,...)
- Images and metadata can be **exported** by the user
- A **delete** button allows the user to delete their history for privacy reason
- An **admin panel** shows how many images have being generated and saved, by how many users and how much storage is left (only accessible to Space owners).

**For optimal UX, a Persistent Storage must be attached to the Space**. If it's not case, the user history will still work but images will be lost when Space restarts. A disclaimer warns the user to export their creation to save them properly.

[Here is a demo Space](https://huggingface.co/spaces/Wauplin/gradio-user-history) showcasing the _User History_ feature. You can also find it on popular Spaces like [AP123/IllusionDiffusion](https://huggingface.co/spaces/AP123/IllusionDiffusion) and [warp-ai/Wuerstchen](https://huggingface.co/spaces/warp-ai/Wuerstchen).

Please let me know if you have any questions!

### Preview:

_(Wurstchen Space)_


app.py

@@ -4,7 +4,7 @@ import torch
 
 from diffusers import DiffusionPipeline
 from free_lunch_utils import register_free_upblock2d, register_free_crossattn_upblock2d
-
+import gradio_user_history as gr_user_history
 
 
 model_id = "stabilityai/stable-diffusion-2-1"
@@ -21,7 +21,7 @@ sd_options_prev = None
 seed_prev = None 
 sd_image_prev = None
 
-def infer(prompt, sd_options, seed, b1, b2, s1, s2):
+def infer(prompt, sd_options, seed, b1, b2, s1, s2, profile: gr.OAuthProfile | None):
     global prompt_prev
     global sd_options_prev
     global seed_prev
@@ -65,6 +65,9 @@ def infer(prompt, sd_options, seed, b1, b2, s1, s2):
     # First SD, then freeu
     images = [sd_image, freeu_image]
 
+    gr_user_history.save_image(label=prompt + ' (SD)', image=sd_image, profile=profile, metadata={"prompt": prompt, "pipe": sd_options, "b1": 1.0, "b2": 1.0, "s1": 1.0, "s2": 1.0})
+    gr_user_history.save_image(label=prompt + ' (FreeU)', image=freeu_image, profile=profile, metadata={"prompt": prompt, "pipe": "freeu", "b1": b1, "b2": b2, "s1": s1, "s2": s2})
+
     return images
 
 
@@ -209,7 +212,12 @@ with block:
                              maximum=1000,
                              step=1,
                              value=42)
-                    
+
+    with gr.Group():
+        with gr.Row():
+            with gr.Accordion("Past generations", open=False):
+                gr_user_history.render()
+    
     with gr.Row():
         with gr.Group():
             # btn = gr.Button("Generate image", scale=0)