fix(tx): fix WitnessRule and WitnessCondition deserialization

[ixje]

fixes https://github.com/CityOfZion/neon-js/issues/872

• WitnessRule deserialization failed because the type had to be converted to int first
• BooleanAndCondition deserialization failed because !!"00" evaluated to true not false.
• AndCondition deserialization failed because this was undefined when called here https://github.com/CityOfZion/neon-js/blob/7eb101aa22d92df1bf50a0e0b7e43b2c43f0ecd6/packages/neon-core/src/tx/components/WitnessCondition.ts#L95