Add Copernicus World-DEM-30 license

[AlexDo1]

The Copernicus World-DEM-30 has a specific license, which is described here: https://docs.sentinel-hub.com/api/latest/static/files/data/dem/resources/license/License-COPDEM-30.pdf

We need to add this license to metacatalog (the license will exclusively be used for the DEM).

We can do "everything" with the DEM:

Article 4. Right of Use
The Licensor grants to the User the following non-exclusive rights of use regarding the Copernicus WorldDEM-30:
(a) reproduction;
(b) distribution;
(c) communication to the General Public;
(d) adaptation, modification and combination with other data and information.

I'm not sure if it is enough to just link the license to the DEM entry. According to the license, we also need to use the following note when we distribute the DEM:

© DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS
by the European Union and ESA; all rights reserved.

And where we use or modify the DEM (tools!), we need to use this note:

"produced using Copernicus WorldDEM-30 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH
2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved”

@mmaelicke do you think it is the right approach to add this specific license to metacatalog?

[AlexDo1]

In general, I think that we need to think about how we cite the data that is used by the tools and make sure that everything is cited correctly.

[mmaelicke]

We use Entry.citation to store the specific requirement how to cite the datasouce. The statement used on modification should be added to the Entry.abstract to inform the user, that the data source has to be cited in a specific way.