Core - Make LegacyJavascriptBindingEnabled obsolete

Will likely be removed in the future as it's been replaced.
Setting after creating your ChromiumWebBrowser instance also doesn't work

Issue #2977

Author: amaitland

CefSharp/CefSharpSettings.cs

@@ -25,12 +25,15 @@ static CefSharpSettings()
         }
 
         /// <summary>
-        /// Objects registered using RegisterJsObject and RegisterAsyncJsObject
+        /// Objects registered using <see cref="IJavascriptObjectRepository.Register"/>
         /// will be automatically bound when a V8Context is created. (Soon as the Javascript
         /// context is created for a browser). This behaviour is like that seen with Javascript
         /// Binding in version 57 and earlier.
-        /// NOTE: Set this before your first call to RegisterJsObject or RegisterAsyncJsObject
+        /// NOTE: MUST be set before creating your first ChromiumWebBrowser instance.
         /// </summary>
+        [Obsolete("Use chromiumWebBrowser.JavascriptObjectRepository.Settings.LegacyBindingEnabled = true; instead." +
+            "Must be called before creating your first ChromiumWebBrowser instance." +
+            "See https://github.com/cefsharp/CefSharp/issues/2977 for details.")]
         public static bool LegacyJavascriptBindingEnabled { get; set; }
 
 #if !NETCOREAPP