Add milli prefix for Molality.MolePerKilogram (#1403)

Add Milli prefix for MolePerKilogram to capture MillimolePerKilogram.
close #1402

Author: Martian42

Common/UnitDefinitions/Molality.json

@@ -12,11 +12,12 @@
       "SingularName": "MolePerKilogram",
       "PluralName": "MolesPerKilogram",
       "BaseUnits": {
-		"N": "Mole",
+        "N": "Mole",
         "M": "Kilogram"
       },
       "FromUnitToBaseFunc": "{x}",
       "FromBaseToUnitFunc": "{x}",
+      "Prefixes": [ "Milli" ],
       "Localization": [
         {
           "Culture": "en-US",

Common/UnitEnumValues.g.json

@@ -1807,7 +1807,8 @@
   },
   "Molality": {
     "MolePerGram": 4,
-    "MolePerKilogram": 1
+    "MolePerKilogram": 1,
+    "MillimolePerKilogram": 2
   },
   "Radioactivity": {
     "Becquerel": 7,

UnitsNet.NanoFramework/GeneratedCode/Quantities/Molality.g.cs

@@ -11,5 +11,6 @@ public class MolalityTests : MolalityTestsBase
 
         protected override double MolesPerKilogramInOneMolePerKilogram => 1;
         protected override double MolesPerGramInOneMolePerKilogram => 1e-3;
+        protected override double MillimolesPerKilogramInOneMolePerKilogram => 1e3;
     }
 }

UnitsNet.NanoFramework/GeneratedCode/Units/MolalityUnit.g.cs

@@ -1,2 +1,3 @@
+MillimolesPerKilogram=mmol/kg
 MolesPerGram=mol/g
 MolesPerKilogram=mol/kg