Loading files from multiple drives

[mariustk]

Describe the bug
When loading file from two separate network drives there is an issue with path resolving

To Reproduce
Steps to reproduce the behavior:

1. Load a pickle file from one drive (probably occurring with all formats)
2. Load a pickle file from another drive

Expected behavior
Expect to be able to load files located on multiple network drives

Screenshots

Traceback (most recent call last):
  File "C:\Interpreters\Instruct_with_sifio\Lib\site-packages\qats\app\gui.py", line 1421, in update_model
    names = self.db.list(names="*", relative=True, display=False)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Interpreters\Instruct_with_sifio\Lib\site-packages\qats\tsdb.py", line 1265, in list
    match = [self._path_relpath(_, common) for _ in match]
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Interpreters\Instruct_with_sifio\Lib\site-packages\qats\tsdb.py", line 1265, in <listcomp>
    match = [self._path_relpath(_, common) for _ in match]
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Interpreters\Instruct_with_sifio\Lib\site-packages\qats\tsdb.py", line 365, in _path_relpath
    return os.path.relpath(key, start)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen ntpath>", line 766, in relpath
ValueError: path is on mount 'Y:', start on mount 'C:'