refactor(cmake): simplify ImGui test engine integration and feature flags

- Updated CMake configuration to always include the ImGui Test Engine when tests are enabled, removing conditional checks for UI tests.
- Simplified feature flag management by enabling JSON and gRPC by default, with a minimal build option to disable only the most expensive features.
- Enhanced status messages to provide clearer feedback on build configurations and feature availability.

Benefits:
- Streamlined integration of the ImGui Test Engine for testing purposes.
- Improved clarity in feature flag settings, making it easier to manage build configurations.

cmake/imgui.cmake

@@ -12,31 +12,21 @@ target_include_directories(ImGui PUBLIC ${SDL2_INCLUDE_DIR})
 target_compile_definitions(ImGui PUBLIC
   IMGUI_IMPL_OPENGL_LOADER_CUSTOM=<SDL2/SDL_opengl.h>  GL_GLEXT_PROTOTYPES=1)
 
-# Set up ImGui Test Engine sources and target conditionally
-if(YAZE_ENABLE_UI_TESTS)
+# ImGui Test Engine - Always built when tests are enabled for simplified integration
+# The test infrastructure is tightly coupled with the editor, so we always include it
+if(YAZE_BUILD_TESTS)
   set(IMGUI_TEST_ENGINE_PATH ${CMAKE_SOURCE_DIR}/src/lib/imgui_test_engine/imgui_test_engine)
   file(GLOB IMGUI_TEST_ENGINE_SOURCES ${IMGUI_TEST_ENGINE_PATH}/*.cpp)
   add_library("ImGuiTestEngine" STATIC ${IMGUI_TEST_ENGINE_SOURCES})
   target_include_directories(ImGuiTestEngine PUBLIC ${IMGUI_PATH} ${CMAKE_SOURCE_DIR}/src/lib)
   target_link_libraries(ImGuiTestEngine PUBLIC ImGui)
-  
-  # Enable test engine definitions only when UI tests are enabled
   target_compile_definitions(ImGuiTestEngine PUBLIC 
     IMGUI_ENABLE_TEST_ENGINE=1 
     IMGUI_TEST_ENGINE_ENABLE_COROUTINE_STDTHREAD_IMPL=1)
   
-  # Also define for targets that link to ImGuiTestEngine
-  set(IMGUI_TEST_ENGINE_DEFINITIONS 
-    IMGUI_ENABLE_TEST_ENGINE=1 
-    IMGUI_TEST_ENGINE_ENABLE_COROUTINE_STDTHREAD_IMPL=1)
-  
-  # Make ImGuiTestEngine target available
-  set(IMGUI_TEST_ENGINE_TARGET ImGuiTestEngine)
+  message(STATUS "✓ ImGui Test Engine enabled (tests are ON)")
 else()
-  # Create empty variables when UI tests are disabled
-  set(IMGUI_TEST_ENGINE_SOURCES "")
-  set(IMGUI_TEST_ENGINE_TARGET "")
-  set(IMGUI_TEST_ENGINE_DEFINITIONS "")
+  message(STATUS "✗ ImGui Test Engine disabled (tests are OFF)")
 endif()
 
 set(