Update: Strip NULLs from the payload number converters.

Update: Strip NULLs from the payload number converters.

Add logic to strip the NULLs from the numbers.
The FSS functions use NULLs to reduce reallocations but the payload sends everything.

Don't introduce unexpected NULLs when writing the numbers.

I need to review the logic for any mistakes which I find is often best after sleeping on it.
Even better, I should write some unit tests to expose any potential logic flaws more easily.