Add TestEditor class and integration test setup for ImGui; implement basic UI elements and test registration functionality.

test/test_editor.h

@@ -0,0 +1,60 @@
+#ifndef YAZE_TEST_INTEGRATION_TEST_EDITOR_H
+#define YAZE_TEST_INTEGRATION_TEST_EDITOR_H
+
+#include "app/editor/editor.h"
+#include "imgui_test_engine/imgui_te_context.h"
+#include "imgui_test_engine/imgui_te_engine.h"
+
+namespace yaze {
+namespace test {
+
+class TestEditor : public yaze::editor::Editor {
+ public:
+  TestEditor() = default;
+  ~TestEditor() = default;
+  void Initialize() override {
+
+  }
+
+  absl::Status Cut() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+  absl::Status Copy() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+  absl::Status Paste() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+
+  absl::Status Undo() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+  absl::Status Redo() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+
+  absl::Status Find() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+
+  absl::Status Update() override;
+
+  absl::Status Save() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+  absl::Status Load() override {
+    return absl::UnimplementedError("Not implemented");
+  }
+
+  void RegisterTests(ImGuiTestEngine* engine);
+
+ private:
+  ImGuiTestEngine* engine_;
+};
+
+int RunIntegrationTest();
+
+}  // namespace test
+}  // namespace yaze
+
+#endif  // YAZE_TEST_INTEGRATION_TEST_EDITOR_H