Support TextHeightBasis all the way up to MongolText #49
Description
#47 adds TextHeightBasis (similar to TextWidthBasis for Text) at the lower levels (ex, MongolTextPainter) but not all the way up to MongolText. This affects whether the widget height is the height of the parent when line wrapping or the height of the longestLine. The default right now is parent.
This issue is to track the work to add TextHeightBasis to the rest of the classes that are missing it.