change signature of refraction to let caller know if refraction occurs or not

src/vec4.c

@@ -431,7 +431,7 @@ glmc_vec4_reflect(vec4 I, vec4 N, vec4 dest) {
 }
 
 CGLM_EXPORT
-void
+bool
 glmc_vec4_refract(vec4 I, vec4 N, float eta, vec4 dest) {
-  glm_vec4_refract(I, N, eta, dest);
+  return glm_vec4_refract(I, N, eta, dest);
 }