Fix number and boolean validator

There are 2 problems in validators,

First in NumberValidator:
If our input has a zero value, the return value type is a string.
If our input has empty => true rule and the input is empty, return value is an empty string, It's better to use NullValue.

And second in BooleanValidator: If our input has an 0 value, it does not exist in the output of check inputs.