HPCC-10650 createSingleFileClone don't remove files unless changed

When overwrite is specified, cloning a remote file should not delete
a local instance unless the file has changed in a significant way.

cloneFrom info should be updated in case the user is trying to change
where the file gets copied from (source dfs ip, cluster, etc).

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>