Introduced extension method for dictionaries for getting the desired value or a default value if the key does not exist

Author: szv

src/Codebreaker.ViewModels/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,7 @@
+namespace System.Collections.Generic;
+
+internal static class DictionaryExtensions
+{
+    public static TValue? GetOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, TValue? defaultValue = default) =>
+        dictionary.TryGetValue(key, out var value) ? value : defaultValue;
+}