Menu of components (#131)

Allow Container::Vertical and Container::Horizontal to have an
external selector, similar to Container::Tab.

This is useful for implementing a menu of menu.

Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

examples/component/homescreen.cpp

@@ -362,7 +362,7 @@ int main(int argc, const char* argv[]) {
 
   bool refresh_ui_continue = true;
   std::thread refresh_ui([&] {
-    while(refresh_ui_continue) {
+    while (refresh_ui_continue) {
       using namespace std::chrono_literals;
       std::this_thread::sleep_for(0.05s);
       shift++;