Returns the first non-zero number or non-empty string from the provided list of parameters.
Ignores None, zero (or near-zero), infinite, or empty strings.
If no valid parameter is found, returns None.
defnz(value1, value2, [value3, ...])
defnz(0, nan(), none(), 3.5, 4); // returns 3.5 as the first valid non-zero number
defnz(none(), "", "Hello", "World"); // returns "Hello" as the first non-empty string
defnz(0, none(), "", 0, nan()); // returns None, since all are zero/empty