Potential licensing issue with szip.dll

HDF.PInvoke ships with SZIP in `native/HDF5 1.10/bin64/szip.dll`. According to the SZIP library is licensed restrictively, only allowing non-commercial use without a paid license.

However, the `COPYING` file in the repository root does not state that restriction and the [license of the NuGet package](http://www.hdfgroup.org/ftp/HDF5/current/src/unpacked/COPYING) states:

> HDF5 is available with the SZIP compression library but SZIP is not part
> of HDF5 and has separate copyright and license terms. See “Szip Compression
> in HDF Products” (https://support.hdfgroup.org/doc_resource/SZIP/) for
> further details.

Thus by solely reading the licensing terms, I would believe that the HDF.PInvoke NuGet package is free to use both for commercial and non-commercial products, which is indeed not the case due to the SZIP restrictions.