Refactor tests for processing and adapt it to new library structure, plus fix...

Refactor tests for processing and adapt it to new library structure, plus fix unit tests for processing

qim3d/io/_convert.py

@@ -8,7 +8,7 @@ import tifffile as tiff
 import zarr
 from tqdm import tqdm
 
-from qim3d.utils import stringify_path
+from qim3d.utils._misc import stringify_path
 from qim3d.io import save