Replace usage of the HERE CLI with the xyz-spaces-python package

[felixvanoost]

Until recently, the HERE CLI was the easiest way to upload geospatial data to a HERE XYZ space for viewing. Earlier this year, HERE began development of a native Python library for HERE XYZ, xyz-spaces-python, which should make both development and user installation much easier. The tool should be updated to replace usage of the HERE CLI with xyz-spaces-python with basic feature parity.