portal: additional buttons on list pages

link to onion services page from origin page
link to previews of distribution lists from lists

app/lists/mirror_mapping.py

@@ -4,7 +4,6 @@ from typing import Dict, List
 from pydantic import BaseModel, Field
 from tldextract import extract
 
-from app import app
 from app.models.base import Group
 from app.models.mirrors import Proxy
 
@@ -31,6 +30,7 @@ class MirrorMapping(BaseModel):
 
 
 def mirror_mapping():
+    from app import app
     return MirrorMapping(
         version="1.1",
         mappings={