get the contents for the folder, This includes subfolders and uploads. array example:
[0] => Array
[folder_pk] => 1
[folder_name] => Software Repository
[1] => Array
[folder_pk] => 5
[folder_name] => cpio
[2] => Array
[upload_pk] => 123
[upload_filename] =>cpio-1.2.3.rpm
[uploadtree_pk] => 987653 (top level uploadtree_pk for this upload)

Returns: $FolderContents array: