Unexpected behaviors in `omerotools`: `parse_url` and `upload_image_to_omero`

[loicsauteur]

Hi all

while testing your OMERO_batch_projection.py script I noticed:

parse_url:

1. Lines 113-117 should be removed (they do not do anything)
2. Does not work with plain dataset ID. Running on dataset IDs results in an error.
   This would require checking if the supplied ID (e.g. 12345) is a Dataset, Project, or Image.

upload_image_to_omero:
It would be nice if it would check if the path exists and if not: raise a FileNotFoundError.

I can do a PR if you like, let me know!