Load data from GoCAD

[Leguark]

Dom has done already a function on simpeg to read at least one of the formats

https://programtalk.com/vs2/python/12012/simpeg/SimPEG/Utils/io_utils.py/

[RichardScottOZ]

I have done a bit of work on this, too, extending what he made.

[RichardScottOZ]

https://github.com/RichardScottOZ/GOCAD_TS-Surface-Reader