Differentiate datasets based on origin

[kalxas]

Datasets should be split into 3 categories:

• native: datasets created within CKAN from metadata editor
• imported: datasets created from uploading an XML file with valid metadata (ISO, DC etc). The original file has to be kept in the database, even if changes occur through metadata editor (changes are permitted)
• harvested: datasets that have been harvested from external catalogs (CSW, CKAN, PublicaMundi, WAF, OpenDataJSON etc). The original file has to be kept and changes are not permitted.