Add getM() and getJ() - separate inside/outside checks from core functions

[OrtnerMichael]

Core functions are trimmed to performance, the mask generation for inside-outside-edge checks take a lot of time. In most cases users know whether they are inside or outside. One more use of it is to refactor the code to enable the calculation of getM and getJ.

• can inside-outside checks be separated from core computation ?
• can they be turned on and off in a practical manner ?
• Add getM()
• Add getJ()

Note

in_out is currently an unused option in magnet_trimesh_field

to clarify:

• H-field inside for Cylinder and Cylinder Segment does not match #703

• Circle, Polyline, Triangle, Dipole -> what are getM and getJ outputs ?

• Sphere -> cannot use a generic convert_BHMJ because of polarization/3 factor. What about this factor when calculating getM and getJ

[OrtnerMichael]

• moving to Version 5 #647

[Alexboiboi]

Reopening this as not addressed. Can still be tracked in #647