Improve hash for BSDF hemisphere

[vidanovic]

For optical layer IGU hashing BSDFHemisphere class (from WindowsCalc-Engine) is not fully hashed but only size is taken into account.

WinCalc/src/layer_cache.h

Lines 11 to 26 in 0c87e46

	struct LayerCacheKey {
	std::string method_name;
	Spectal_Data_Wavelength_Range_Method wavelength_method;
	int number_visible_bands;
	int number_solar_bands;
	size_t bsdf_direction_count; // new addition
	bool operator==(const LayerCacheKey & other) const {
	return method_name == other.method_name &&
	wavelength_method == other.wavelength_method &&
	number_visible_bands == other.number_visible_bands &&
	number_solar_bands == other.number_solar_bands &&
	bsdf_direction_count == other.bsdf_direction_count;
	}
	};
	}

Make sure to extend hashing to cover for all the classes in BSDFHemisphere.

NOTE: This will currently produce incorrect results if Glazing_System is called consecutively with different BSDF hemispheres that have the same size.