Uses b2_list_file_versions to retrieve all file versions, and returns
the one that was active at the specified time
This is especially useful in combination with other backup tools, such
as restic, which may use rclone as a backend.
Similar to fs.Duration but parses into a timestamp instead
Supports parsing from:
* Any of the date formats in parseTimeDates
* A time.Duration offset from now
* parseDurationSuffixes offset from now
SwazRGB