Move Utah teapot model reading code into dedicated module

main.c

@@ -1,5 +1,5 @@
 #include "gpu.h"
-#include "model.h"
+#include "model_format_utah.h"
 
 #include <assert.h>
 #include <math.h>
@@ -51,7 +51,7 @@ int main(int argc, char *argv[])
 		fprintf(stderr, "Usage: %s PATH/TO/MODEL\n", argv[0]);
 		return 1;
 	}
-	model_t model = model_read(argv[1]);
+	model_t model = model_format_utah_read(argv[1]);
 
 	// Set up window
 	glfwInit();