Exception on copying from a WebDAV network drive

Hi!

I'm not sure is this a bug or a not-yet-ready feature (#33), so I create a new ticket. I got an exception in Windows version after I'd tried to copy a directory (Z:\backup\) from a network drive (WebDAV) to an internal HDD. WebDAV provider is Yandex.Disk.

Command 'Copy' raised error.

Traceback (most recent call last):
  File "fman\impl\plugins\command_registry.py", line 128, in _execute_command
  File "C:\Users\EvgeniiChernyi\AppData\Local\fman\Versions\1.4.3\Plugins\Core\core\commands\__init__.py", line 502, in __call__
    proceed = self._confirm_tree_operation(files, dest_dir, src_dir)
  File "C:\Users\EvgeniiChernyi\AppData\Local\fman\Versions\1.4.3\Plugins\Core\core\commands\__init__.py", line 575, in _confirm_tree_operation
    if len(files) == 1 and fs.samefile(dest_url, files[0]):
  File "fman\fs.py", line 45, in samefile
  File "fman\impl\plugins\mother_fs.py", line 123, in samefile
  File "fman\impl\plugins\mother_fs.py", line 120, in resolve
  File "C:\Users\EvgeniiChernyi\AppData\Local\fman\Versions\1.4.3\Plugins\Core\core\fs\local\__init__.py", line 180, in resolve
    path = Path(path).resolve()
  File "pathlib.py", line 1109, in resolve
  File "pathlib.py", line 186, in resolve
OSError: [WinError 1] Incorrect function: 'Z:\\backup'

Start with _confirm_tree_operation in core/commands/init.py and trace fs.samefile through fman/fs.py, fman/impl/plugins/mother_fs.py, and core/fs/local/init.py. Reproduce copying a directory from the reported WebDAV drive on Windows; done means the Copy command no longer raises the shown WinError for that operation.