ExactMatcher : IgnoreCase (#817)

* ...

* mm

* fix some null warnings

* fx

src/WireMock.Net/Util/DictionaryExtensions.cs

@@ -17,6 +17,7 @@ public static class DictionaryExtensions
     /// <param name="dictionary">The dictionary to loop (can be null).</param>
     /// <param name="action">The action.</param>
     public static void Loop<TKey, TValue>(this IDictionary<TKey, TValue>? dictionary, Action<TKey, TValue> action)
+        where TKey : notnull
     {
         Guard.NotNull(action);
 

src/WireMock.Net/Util/TypeBuilderUtils.cs

@@ -32,7 +32,7 @@ internal static class TypeBuilderUtils
             CreateGetSetMethods(typeBuilder, property.Key, property.Value);
         }
 
-        var type = typeBuilder.CreateTypeInfo().AsType();
+        var type = typeBuilder.CreateTypeInfo()!.AsType();
 
         Types.TryAdd(properties, type);
 
@@ -43,6 +43,7 @@ internal static class TypeBuilderUtils
     /// https://stackoverflow.com/questions/3804367/testing-for-equality-between-dictionaries-in-c-sharp
     /// </summary>
     private static bool Compare<TKey, TValue>(IDictionary<TKey, TValue> dict1, IDictionary<TKey, TValue> dict2)
+        where TKey : notnull
     {
         if (dict1 == dict2)
         {