Added missing bindings for matrix

[0xDiddi]

• .TransformPoint(...) has been proven to work on mac
• .TransformSize(...) should therefore work as well as it's basically the same
• vs code also ran go fmt so there's that

[0xDiddi]

I'm cleaning up my github, and due to complete lack of interest in the past ... checks calendar ... almost three years, I'll be closing this PR and deleting the changed branch.

If, for some reason, anyone else happens to need these changes at some point, the relevant modifications to the draw.go file are given below:

func (m *DrawMatrix) TransformPoint(x float64, y float64) (xout float64, yout float64) {
    cm := m.toLibui()
    cx, cy := C.double(x), C.double(y)
    C.uiDrawMatrixTransformPoint(cm, &cx, &cy)
    C.pkguiFreeMatrix(cm)
    return float64(cx), float64(cy)
}

func (m *DrawMatrix) TransformSize(x float64, y float64) (xout float64, yout float64) {
    cm := m.toLibui()
    cx, cy := C.double(x), C.double(y)
    C.uiDrawMatrixTransformSize(cm, &cx, &cy)
    C.pkguiFreeMatrix(cm)
    return float64(cx), float64(cy)
}

I give no guarantees of any kind that this still works, all I can say is that "it worked on my machine™" 3 years ago.