Validator should be able to normalize received functions.

[proofit404]

State should receive normalized object returned validator.

If variable or argument has more than one validator, we should check there is no conflict.

• normalize variable assignment (simple and composition (success and conflict))
• normalize story argument (simple and composition (success and conflict))
• validation error variable assignment (simple and composition)
• validation error story argument (simple and composition)

In addition all cases above should be tested with sequential nested stories:

C1(
    B1(
         A1(), # defines a1v1
         A2(), # defines a1v1 also
    ),
    B2(
         A3(),
         A4(),
    ),
)