Add modules support (#1015)

Add experimental C++20 module suppport.
Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

src/ftxui/screen/screen.cppm

@@ -0,0 +1,24 @@
+/**
+ * @file screen.cppm
+ * @brief Module file for the Screen class of the Screen module
+ */
+
+module;
+
+#include <ftxui/screen/screen.hpp>
+
+export module ftxui.screen.screen;
+
+/**
+ * @namespace ftxui
+ * @brief The FTXUI ftxui:: namespace
+ */
+export namespace ftxui {
+    namespace Dimension {
+        using ftxui::Dimension::Fixed;
+        using ftxui::Dimension::Full;
+    }
+
+    using ftxui::Image;
+    using ftxui::Screen;
+}