[v3.2.0] Range for dct:spatial in the class Public Organization

[jimjyang]

[I open a new issue, although this in a way was already mentioned in #118 but that issue was related/tagget to the previous version]

The range for the mandatory property spatial (dct:spatial) in the class Public Organization is a specific code list (Administrative Territorial Unit, ATU List). According to CMC-R14 in the SEMIC Style Guide, this way of modelling is used when one wants to be specific which controlled list shall be used.

We agree with the usage note for this property, which says "In Europe, this is likely to be the Administrative Territorial Units Named Authority List maintained by the Publications Office's", i.e., not the one and only code list for this property.

Similar to the property spatial (dct:spatial) in the class Public Service, we propose therefore to change the range to dct:Location, and to have a similar usage note.

[jimjyang]

BTW1, the URI used behind https://semiceu.github.io/CPSV-AP/releases/3.2.0/#AdministrativeTerritorialUnit, is the URI for atu-type NAL instead of the atu NAL (http://publications.europa.eu/resource/dataset/atu).

This issue is related to CPOV/issues/31.