Fix harvest process for importing license values

[janette]

Currently the license data is entered into a select field. When harvesting the license values are urls and end up in the search facet as unclickable links

Acceptance Criteria

• License values are 'converted' to the select field key values when they match an option that exists. Existing options: https://github.com/GetDKAN/dkan/blob/7.x-1.x/modules/dkan/dkan_dataset/modules/dkan_dataset_content_types/dkan_dataset_content_types.license_field.inc#L64
• Values that do not match an option the 'Other' key is selected and the value saved to 'field_license[und][other]'