Fix cache key for non-Latin sites

Avoiding using Page.__repr__() as it uses the localized namespace name
and encodes the title into the console encoding, which causes problems
when _create_file_name() tries to encode it again.

Bug: 67488

Change-Id: If49039bac8e8347852c1a04963f678903621d2a9
Merge "Fix cache key for non-Latin sites"