Show Buttons in entity editor

- ScriptEngine: Added HasCustomAttribute- extension method
- ScriptEngine: Added Application class

ScriptCore/Core/Application.cs

@@ -1,15 +1,37 @@
 namespace GlitchyEngine.Core;
 
-public class Application
+/// <summary>
+/// Contains information about the application runtime and methods to control it.
+/// </summary>
+public static class Application
 {
     /// <summary>
-    /// Returns true when the script is running in edit mode.
+    /// Returns <see langword="true"/> when the application is running in the editor (any mode e.g. edit mode or play mode).
     /// </summary>
-    /// <seealso cref="IsPlaying"/>
-    public bool IsEditor = false;
+    /// <seealso cref="IsPlayer"/>
+    /// <seealso cref="IsInEditMode"/>
+    /// <seealso cref="IsInPlayMode"/>
+    public static bool IsEditor => ScriptGlue.Application_IsEditor();
+
     /// <summary>
-    /// Returns true when the script is running in play mode or in the player.
+    /// Returns <see langword="true"/> when the application is running in the dedicated player.
     /// </summary>
     /// <seealso cref="IsEditor"/>
-    public bool IsPlaying = false;
+    public static bool IsPlayer => ScriptGlue.Application_IsPlayer();
+
+    /// <summary>
+    /// Returns <see langword="true"/> when the application is running in the editor and the editor is in edit mode.<br/>
+    /// If <see cref="IsEditor"/> is <see langword="false"/> (i.e. the application is not running in the editor), <see cref="IsInEditMode"/> will always be <see langword="false"/>.
+    /// </summary>
+    /// <seealso cref="IsEditor"/>
+    /// <seealso cref="IsInPlayMode"/>
+    public static bool IsInEditMode => ScriptGlue.Application_IsInEditMode();
+
+    /// <summary>
+    /// Returns <see langword="true"/> when the application is running in the editor (<see cref="IsEditor"/> = <see langword="true"/>) and the editor is in play mode. Or when the application in running in the dedicated player (<see cref="IsPlayer"/> = <see langword="true"/>)<br/>
+    /// </summary>
+    /// <seealso cref="IsEditor"/>
+    /// <seealso cref="IsPlayer"/>
+    /// <seealso cref="IsInEditMode"/>
+    public static bool IsInPlayMode => ScriptGlue.Application_IsInPlayMode();
 }