fix: don't over quote forwarded headers

Fix introduced on #15035 is over quoting headers.

Eg mails instead of user@example.com shown as user%40example.com
Eg names instead of First Last shown as First%20Last

Also we are spending some time quoting ids and roles without required.

Keep quote only on user name, initially had problem based on the discussion
https://github.com/open-webui/open-webui/discussions/14391

Also add space in safe characters, in order remove %20 from names.

backend/open_webui/routers/audio.py

@@ -345,10 +345,10 @@ async def speech(request: Request, user=Depends(get_verified_user)):
                         "Authorization": f"Bearer {request.app.state.config.TTS_OPENAI_API_KEY}",
                         **(
                             {
-                                "X-OpenWebUI-User-Name": quote(user.name),
-                                "X-OpenWebUI-User-Id": quote(user.id),
-                                "X-OpenWebUI-User-Email": quote(user.email),
-                                "X-OpenWebUI-User-Role": quote(user.role),
+                                "X-OpenWebUI-User-Name": quote(user.name, safe=" "),
+                                "X-OpenWebUI-User-Id": user.id,
+                                "X-OpenWebUI-User-Email": user.email,
+                                "X-OpenWebUI-User-Role": user.role,
                             }
                             if ENABLE_FORWARD_USER_INFO_HEADERS
                             else {}