Add Micro and Milli prefixes to Frequency (#1182)

* Add Micro and Milli prefixes to Frequency

* Add generated code.

* Add missing tests

Author: Muximize

Common/UnitDefinitions/Frequency.json

@@ -11,7 +11,7 @@
       "PluralName": "Hertz",
       "FromUnitToBaseFunc": "{x}",
       "FromBaseToUnitFunc": "{x}",
-      "Prefixes": [ "Kilo", "Mega", "Giga", "Tera" ],
+      "Prefixes": [ "Micro", "Milli", "Kilo", "Mega", "Giga", "Tera" ],
       "Localization": [
         {
           "Culture": "en-US",

Common/UnitEnumValues.g.json

@@ -504,7 +504,9 @@
     "Megahertz": 8,
     "PerSecond": 9,
     "RadianPerSecond": 10,
-    "Terahertz": 11
+    "Terahertz": 11,
+    "Microhertz": 16,
+    "Millihertz": 21
   },
   "FuelEfficiency": {
     "KilometerPerLiter": 1,

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

@@ -8,6 +8,11 @@ namespace UnitsNet.Tests
     public class FrequencyTests : FrequencyTestsBase
     {
         protected override bool SupportsSIUnitSystem => false;
+        
+        protected override double MicrohertzInOneHertz => 1e6;
+        
+        protected override double MillihertzInOneHertz => 1e3;
+        
         protected override double HertzInOneHertz => 1;
 
         protected override double KilohertzInOneHertz => 1e-3;