extensions/openai: Major openai extension updates & fixes (#3049)

* many openai updates

* total reorg & cleanup.

* fixups

* missing import os for images

* +moderations, custom_stopping_strings, more fixes

* fix bugs in completion streaming

* moderation fix (flagged)

* updated moderation categories

---------

Co-authored-by: Matthew Ashton <mashton-gitlab@zhero.org>

extensions/openai/images.py

@@ -0,0 +1,48 @@
+import os
+import time
+import requests
+from extensions.openai.errors import *
+
+def generations(prompt: str, size: str, response_format: str, n: int):
+    # Stable Diffusion callout wrapper for txt2img
+    # Low effort implementation for compatibility. With only "prompt" being passed and assuming DALL-E
+    # the results will be limited and likely poor. SD has hundreds of models and dozens of settings.
+    # If you want high quality tailored results you should just use the Stable Diffusion API directly.
+    # it's too general an API to try and shape the result with specific tags like "masterpiece", etc,
+    # Will probably work best with the stock SD models.
+    # SD configuration is beyond the scope of this API.
+    # At this point I will not add the edits and variations endpoints (ie. img2img) because they
+    # require changing the form data handling to accept multipart form data, also to properly support
+    # url return types will require file management and a web serving files... Perhaps later!
+
+    width, height = [ int(x) for x in size.split('x') ]  # ignore the restrictions on size
+
+    # to hack on better generation, edit default payload.
+    payload = {
+        'prompt': prompt,  # ignore prompt limit of 1000 characters
+        'width': width,
+        'height': height,
+        'batch_size': n,
+        'restore_faces': True, # slightly less horrible
+    }
+
+    resp = {
+        'created': int(time.time()),
+        'data': []
+    }
+
+    # TODO: support SD_WEBUI_AUTH username:password pair.
+    sd_url = f"{os.environ['SD_WEBUI_URL']}/sdapi/v1/txt2img"
+
+    response = requests.post(url=sd_url, json=payload)
+    r = response.json()
+    if response.status_code != 200 or 'images' not in r:
+        raise ServiceUnavailableError(r.get('detail', [{'msg': 'Unknown error calling Stable Diffusion'}])[0]['msg'], code = response.status_code)
+    # r['parameters']...
+    for b64_json in r['images']:
+        if response_format == 'b64_json':
+            resp['data'].extend([{'b64_json': b64_json}])
+        else:
+            resp['data'].extend([{'url': f'data:image/png;base64,{b64_json}'}])  # yeah it's lazy. requests.get() will not work with this
+
+    return resp