Show SDL version in the About tab (#16046)

irr/include/IrrlichtDevice.h

@@ -16,6 +16,7 @@
 #include "IrrCompileConfig.h"
 #include "position2d.h"
 #include "SColor.h" // video::ECOLOR_FORMAT
+#include <string>
 #include <variant>
 
 namespace irr
@@ -332,6 +333,12 @@ public:
 	used. */
 	virtual E_DEVICE_TYPE getType() const = 0;
 
+	//! Get the version string of the underlying system (e.g. SDL)
+	virtual std::string getVersionString() const
+	{
+		return "";
+	}
+
 	//! Get the display density in dots per inch.
 	//! Returns 0.0f on failure.
 	virtual float getDisplayDensity() const = 0;