Improve actor icons handling and admin

app/media.py

@@ -0,0 +1,20 @@
+import base64
+
+from app.config import BASE_URL
+
+SUPPORTED_RESIZE = [50, 740]
+
+
+def proxied_media_url(url: str) -> str:
+    if url.startswith(BASE_URL):
+        return url
+
+    return "/proxy/media/" + base64.urlsafe_b64encode(url.encode()).decode()
+
+
+def resized_media_url(url: str, size: int) -> str:
+    if size not in SUPPORTED_RESIZE:
+        raise ValueError(f"Unsupported resize {size}")
+    if url.startswith(BASE_URL):
+        return url
+    return proxied_media_url(url) + f"/{size}"