Add annotation property unique individual identifier and some IPCC sector indiviuals

[l-emele]

This issue partially solves #461:

• Add annotation property 'unique individual identifier': A unique individual identifier is an alternative term that is unique for one individual of a class. Unique individual identifiers follow usually a structure defined e.g. by a sector division.
• Add some IPCC sector individuals as start for populating sector individuals. (Further individuals will be implemented later.)

[Vera-IER]

I see that the unique individual identifier is defined in OEO social. Could it still be used for classes in the OEO physical?

[l-emele]

I see that the unique individual identifier is defined in OEO social. Could it still be used for classes in the OEO physical?

So shall we move it to oeo-shared?

[Vera-IER]

Yes, I think this identifier could also be helpful for physical classes.

[l-emele]

@akleinau : Could you please give me some advice how to move the unique individual identifier from oeo-social to oeo-shared without braking anything?

[akleinau]

it should work when you open a text editor and copy the code lines for the annotation over

[stap-m]

Please also update the changelog file

[l-emele]

I've added the definitions and updated CHANGELOG.md.

[l-emele]

I've merged but I've intentionally not deleted the branch feature/sector-division-461 as this PR only partially resolved issue #461.