Provide option to use checksum (e.g. MD5) to compare and validate source and remote files

[WayneSherman]

rclonesync-V2 uses rclone lsl to cache file metadata to speed up compare operations. The lsl output does not include checksums, so there isn't a way to confirm the local and remote files are are binary match of each other.

Using "rclone remote:path lsjson --hash" to cache file metadata provides hashes (if available) which can be used for comparison operations and to validate uploads and downloads to confirm that local and remote files are binary matches.

Making use of the hashes will provide higher confidence of file integrity, and caching them can speed up the compare operation. At present, rclone sync --checksum can take a long time since it has to compute local hashes on every run.

See also:
RClone should support a cache of checksums for local files to avoid redundant work
Cache MD5s
rclone md5sum