Add EUPL-1.2 License option

[tvanriel]

The European Union Public Licence is a free software licence that is drafted and maintained by the European Commission. It focuses on being consistent with the copyright laws in all EU Member States.

The licence is available in all 23 languages of the European Union.

Although initially intended for use by the IDABC programme, it has seen broader adoption in the wider software community.

The license text, in its entirety has been obtained from: https://joinup.ec.europa.eu/sites/default/files/custom-page/attachment/2020-03/EUPL-1.2%20EN.txt

For more information, see: https://spdx.org/licenses/EUPL-1.2.html