[PLA-801][external] fetch_remote_files() is called with an old, V1 argument

[JBWilkie]

Problem

• Changes made to darwin-py in 0.8.58 to remove V1 code removed a V1 backwards compatibility "handler" for an older version of a filter parameter when retrieving a list of remote files in fetch_remote_files()

Solution

• Re-add this backward compatibility and update all invocations of fetch_remote_files() to use item_names instead of filenames

Changelog

• Re-added backward compatibility for a V1 filter parameter when fetching remote files

[linear]

PLA-801 BUG: fetch_remote_files() is called with an incorrect argument in darwin-py 0.8.58

[saurbhc]

LGTM 🙏