Added SOD-128

Datasheet: https://assets.nexperia.com/documents/package-information/SOD128.pdf

I used the same structure as D_SOD-123F, but I only get the right 3D (0.45mm pin length) with the following parameters:

  D1: 3.8
  E1: 2.5
  E: 3.4

I don't know why. According to the above drawing, they should be:

  D1: 3.8
  E1: 2.5
  E: 4.7 # Should be D?

Pin length is calculated as:

    if params['L']:
        L  = params['L']
    else:
        L = (E-E1_b)/2

I think there is an error in the generator. Pin length should be calculated as D-D1/2, if rotation is zero (this case), or E-E1/2 if rotation is +/-90 (as the current generator does).

I'm holding the 3D MR until this is clarified...