Add maxwell and oersted as units

modules/core/dimensions.nbt

@@ -29,6 +29,7 @@ dimension Resistance = Voltage / Current
 dimension Conductance = 1 / Resistance
 dimension MagneticFluxDensity = Force / (Charge × Speed)
 dimension MagneticFlux = MagneticFluxDensity × Area
+dimension MagneticFieldStrength = Current / Length
 dimension Inductance = MagneticFlux / Current
 
 dimension Temperature

modules/units/cgs.nbt

@@ -8,3 +8,10 @@ unit dyne: Force = 1e-5 N
 unit erg: Energy = 1 dyn cm
 
 unit gauss: MagneticFluxDensity = 100 µT
+
+@aliases(Mx)
+unit maxwell: MagneticFlux = 1 gauss × cm^2
+assert_eq(1 maxwell, 1e-8 weber)
+
+@aliases(Oe: short)
+unit oersted: MagneticFieldStrength = 1 / (4 pi) * dyne / maxwell