Fix position of block creation window (#72)

Author: iTris666

com.unity.visualeffectgraph/Editor/FilterPopup/VFXFilterWindow.cs

@@ -208,6 +208,12 @@ private static object Invoke(Type t, object inst, string method, params object[]
             return mi.Invoke(inst, args);
         }
 
+        void OnLostFocus()
+        {
+            EditorGUI.EndEditingActiveTextField();
+            Close();
+        }
+
         void Init(Vector2 graphPosition, Vector2 screenPosition, IProvider provider)
         {
             m_Provider = provider;
@@ -289,6 +295,7 @@ internal void OnGUI()
 
             if (m_Tree == null)
             {
+                EditorGUI.EndEditingActiveTextField();
                 Close();
                 return;
             }
@@ -398,6 +405,7 @@ private void HandleKeyboard()
                         }
                         if (evt.keyCode == KeyCode.Escape)
                         {
+                            EditorGUI.EndEditingActiveTextField();
                             Close();
                             evt.Use();
                         }
@@ -554,6 +562,7 @@ private void GoToChild(Element e, bool addIfComponent)
         {
             if (m_Provider.GoToChild(e, addIfComponent))
             {
+                EditorGUI.EndEditingActiveTextField();
                 Close();
                 if (m_mainWindow != null)
                 {