[BREAKING] Figure.text: Raise GMTTypeError if text is a sequence when position is given

[seisman]

In Figure.text, when position is given, text is required. If text is not given, it should raise a GMTParameterError (i.e., #4003). If text is a list/tuple, it should raise the GMTTypeError instead.

This PR makes the change and raise GMTTypeError when a list/tuple is passed to text.