Support industry cargo subtype display without waiting amount

[frosch123]

Callback cargo_subtype_display has a special string range, which is not covered by NML.

800..BFF | Display D0xx (D000..D3FF) text without waiting amount.

No idea what syntax could be suitable for NML.

[andythenorth]

I believe FIRS uses these strings in CB 37 results?

https://github.com/andythenorth/firs/blob/master/src/templates/extra_text_primary.pynml#L27