Feat: read numeric

tests/open_xlsx_get_data_with_set_type.phpt

@@ -48,7 +48,7 @@ array(2) {
     [0]=>
     string(5) "Viest"
     [1]=>
-    string(2) "24"
+    int(24)
     [2]=>
     int(1568877706)
   }