ErrorCalculator.h: Add Includes

Adding includes of used stdlib functionality to
`ErrorCalculator.h`

This is generally recommended practice for stability of
include files. I have not done a systematic check yet
but there are tools that can help with this and explain
more on the need:
  https://include-what-you-use.org

include/mgard-x/Utilities/ErrorCalculator.h

@@ -13,6 +13,11 @@
 // #include "../../shuffle.hpp"
 #include "Types.h"
 
+#include <cmath>
+#include <limits>
+#include <vector>
+
+
 namespace mgard_x {
 
 template <typename T> T L_inf_norm(size_t n, const T *data) {
@@ -117,4 +122,4 @@ T PSNR(size_t n, const T *original_data, const T *decompressed_data) {
 
 } // namespace mgard_x
 
-#endif
+#endif