Set the default destination type to "folder"

This is what it was before...

Signed-off-by: Patrick Avery <patrick.avery@kitware.com>

sources/dicom/large_image_source_dicom/assetstore/rest.py

@@ -26,7 +26,7 @@ def _importData(self, assetstore, params, progress):
         """
         user = self.getCurrentUser()
 
-        destinationType = params.get('destinationType', 'folder')
+        destinationType = params['destinationType']
         if destinationType not in ('folder', 'user', 'collection'):
             msg = f'Invalid destinationType: {destinationType}'
             raise RestException(msg)
@@ -76,7 +76,7 @@ def _importData(self, assetstore, params, progress):
                'in the Girder data hierarchy under which to import the files.')
         .param('destinationType', 'The type of the parent object to import into.',
                enum=('folder', 'user', 'collection'),
-               required=True)
+               required=False, default='folder')
         .param('limit', 'The maximum number of results to import.',
                required=False, default=None)
         .param('filters', 'Any search parameters to filter DICOM objects.',