moveDir function
Moves or renames the from directory to the
to the to path.
The to path must NOT exist.
The from path must be a directory.
moveDir first tries to rename the directory, if that
fails due to the to path being on a different device
we fall back to a copy/delete operation.
moveDir("/tmp/", "/tmp/new_dir");
Throws a MoveDirException if:
the from path doesn't exist
the from path isn't a directory
the to path already exists.
Implementation
void moveDir(String from, String to) => waitForEx(
// ignore: discarded_futures
core.moveDir(from, to));