add ExtensionManager implementation

src/app/editor/system/extension_manager.cc

@@ -0,0 +1,37 @@
+#include "extension_manager.h"
+
+#include <vector>
+
+#include "ext/extension.h"
+
+namespace yaze {
+namespace app {
+namespace editor {
+
+void ExtensionManager::RegisterExtension(yaze_extension* extension) {
+  extensions_.push_back(extension);
+}
+
+void ExtensionManager::InitializeExtensions(yaze_editor_context* context) {
+  for (auto& extension : extensions_) {
+    extension->initialize(context);
+  }
+}
+
+void ExtensionManager::ShutdownExtensions() {
+  for (auto& extension : extensions_) {
+    extension->cleanup();
+  }
+}
+
+void ExtensionManager::ExecuteExtensionUI(yaze_editor_context* context) {
+  for (auto& extension : extensions_) {
+    if (extension->extend_ui) {
+      extension->extend_ui(context);
+    }
+  }
+}
+
+}  // namespace editor
+}  // namespace app
+}  // namespace yaze