Allow bookmarks to have empty title and description (#843)

* add migration for merging fields

* remove usage of website title and description

* keep empty website title and description in API for compatibility

* restore scraping in API and add option for disabling it

* document API scraping behavior

* remove deprecated fields from API docs

* improve form layout

* cleanup migration

* cleanup website loader

* update tests

bookmarks/services/bookmarks.py

@@ -26,8 +26,6 @@ def create_bookmark(bookmark: Bookmark, tag_string: str, current_user: User):
         _merge_bookmark_data(bookmark, existing_bookmark)
         return update_bookmark(existing_bookmark, tag_string, current_user)
 
-    # Update website info
-    _update_website_metadata(bookmark)
     # Set currently logged in user as owner
     bookmark.owner = current_user
     # Set dates
@@ -67,13 +65,22 @@ def update_bookmark(bookmark: Bookmark, tag_string, current_user: User):
     if has_url_changed:
         # Update web archive snapshot, if URL changed
         tasks.create_web_archive_snapshot(current_user, bookmark, True)
-        # Only update website metadata if URL changed
-        _update_website_metadata(bookmark)
         bookmark.save()
 
     return bookmark
 
 
+def enhance_with_website_metadata(bookmark: Bookmark):
+    metadata = website_loader.load_website_metadata(bookmark.url)
+    if not bookmark.title:
+        bookmark.title = metadata.title or ""
+
+    if not bookmark.description:
+        bookmark.description = metadata.description or ""
+
+    bookmark.save()
+
+
 def archive_bookmark(bookmark: Bookmark):
     bookmark.is_archived = True
     bookmark.date_modified = timezone.now()
@@ -235,12 +242,6 @@ def _merge_bookmark_data(from_bookmark: Bookmark, to_bookmark: Bookmark):
     to_bookmark.shared = from_bookmark.shared
 
 
-def _update_website_metadata(bookmark: Bookmark):
-    metadata = website_loader.load_website_metadata(bookmark.url)
-    bookmark.website_title = metadata.title
-    bookmark.website_description = metadata.description
-
-
 def _update_bookmark_tags(bookmark: Bookmark, tag_string: str, user: User):
     tag_names = parse_tag_string(tag_string)