Function `to_long()` returns unexpected value when input is float with decimals

As mentioned in https://github.com/bitshares/bitshares-ui/issues/3545#issuecomment-1236207285, the function `to_long()` in `SerializerValidation.js` may return unexpected result if the input is a `float` with decimals (E.G. `12.999999999999998`). Code: https://github.com/bitshares/bitsharesjs/blob/c962b80f625d550573e847e6f1466524109fd3ea/lib/serializer/src/SerializerValidation.js#L103-L116

```
> parseFloat("0.00013")*100000
12.999999999999998
> Long.fromString(""+parseFloat("0.00013")*100000)
Long { low: 1150981118, high: 30, unsigned: false }
> Long.fromString(""+parseFloat("0.00013")*100000).toString()
129999999998
```

To fix this, IMHO, as a library, we shouldn't change user input, but we should require the input to be valid.