implement enum for types, implement OpenDialog from Dialog-API

ElectronNET.API/Entities/Vibrancy.cs

@@ -0,0 +1,21 @@
+using Newtonsoft.Json;
+
+namespace ElectronNET.API.Entities
+{
+    public enum Vibrancy
+    {
+        [JsonProperty("appearance-based")]
+        appearanceBased,
+        light,
+        dark,
+        titlebar,
+        selection,
+        menu,
+        popover,
+        sidebar,
+        [JsonProperty("medium-light")]
+        mediumLight,
+        [JsonProperty("ultra-dark")]
+        ultraDark
+    }
+}