Add support "ENC()" expression for story level

[DKalkaev]

As Vividus user I would like to use "ENC()" expression on story level to use encrypted values.

For the current moment I could use "ENC()" expression only for properties like this
http.auth.password=ENC(encrypted_property_value)

I would like to use ENC() expression in steps like in following way:
Given I initialize scopes variable variableName with value #{ENC(encrypted_property_value)}
Mentioned syntax aligned to using Vividus expressions.

For actual moment ENC() expression cannot be used on story level
Screenshot of allure report