SEGYExport should be able to create file/trace headers if the VDS wasn't imported from SEG-Y

For data scientists it is a valuable feature to be able to export their probability cubes or other similar datasets to SEG-Y in order to read them into software that isn't VDS capable. In order for that to work the SEGYExport tool needs to be able to create its own headers if none are present in the input VDS.