add append support to the files being copied/moved if the source file is bigger then destination folder and the file name is same

we can already set options to overwrite the files in the destination directory based on various options like date and size.

assuming the the file names are same and if source file is bigger then the file in destination folder then we need to append the file in the destination after gaining confirmation from users or possibly having an option to give this acceptance in advance before the file move / copy operations