[Binding] Fix ImNodeEditor minor probs and add Style and Config struct

imgui-binding/src/main/java/imgui/nodeditor/ImNodeEditorConfig.java

@@ -0,0 +1,41 @@
+package imgui.nodeditor;
+
+import imgui.binding.ImGuiStructDestroyable;
+
+public final class ImNodeEditorConfig extends ImGuiStructDestroyable {
+    public ImNodeEditorConfig() {
+    }
+
+    public ImNodeEditorConfig(final long ptr) {
+        super(ptr);
+    }
+
+    /*JNI
+        #include <stdint.h>
+        #include <imgui.h>
+        #include <imgui_node_editor.h>
+        #include <imgui_node_editor_internal.h>
+        #include "jni_binding_struct.h"
+
+        namespace ed = ax::NodeEditor;
+
+        #define IM_NODE_EDITOR_CONFIG ((ed::Config*)STRUCT_PTR)
+     */
+
+    @Override
+    protected long create() {
+        return nCreate();
+    }
+
+    private native long nCreate(); /*
+        return (intptr_t)(new ed::Config());
+    */
+
+    public native String getSettingsFile(); /*
+        return env->NewStringUTF(IM_NODE_EDITOR_CONFIG->SettingsFile);
+    */
+
+    public native void setSettingsFile(String settingsFile); /*MANUAL
+        IM_NODE_EDITOR_CONFIG->SettingsFile = obj_settingsFile == NULL ? NULL : (char*)env->GetStringUTFChars(obj_settingsFile, JNI_FALSE);
+    */
+}