The toFilerPath function should return raw file paths, not URL-escaped
paths. URL escaping was needed when the path was embedded in a URL
(old toFilerUrl), but now that we pass paths directly to putToFiler,
they should be unescaped.
This fixes S3 integration test failures:
- test_bucket_listv2_encoding_basic
- test_bucket_list_encoding_basic
- test_bucket_listv2_delimiter_whitespace
- test_bucket_list_delimiter_whitespace
The tests were failing because paths were double-encoded (escaped when
stored, then escaped again when listed), resulting in %252B instead of
%2B for '+' characters.
Root cause: When we removed URL parsing in putToFiler, we should have
also removed URL escaping in toFilerPath since paths are now used
directly without URL encoding/decoding.