FindHDF5: various fixes, mostly for Windows
- when using NO_MODULE add version number, handle a few more HDF5 versions such as 1.8.18 that used targets hdf5::hdf5-static etc, define HDF5_DEFINITIONS from target properties (which should set H5_BUILT_AS_DYNAMIC_LIB for shared targets on HDF5 1.8.18 or later), do not find the dll but use the import-lib by checking IMPLIB target property.
- when not using a hdf5-config, do not search for a dll.