fix(ConstTypes): size should be same as in type

src/ConstString.js

@@ -14,6 +14,9 @@ ConstString.prototype.serialize = function(dv, src) {
   if (dv.byteLength < encoded.byteLength) {
     throw new Error('too small buffer')
   }
+  if (src.length != this._size) {
+    throw new Error('string should be ' + this._size + ' symbols length')
+  }
 
   memcpy(dv, encoded)
   return