Data builders do not support inline classes

[martinbonnin]

Description

Initially reported by @sebj on slack

Using a builtin mapping with the default inline classes generation breaks data builders:

extend scalar DateTime @mapTo(builtIn: String)

Generated code:

  public var createdAt: DateTime by BuilderProperty(StringAdapter)

BuilderProperty(StringAdapter) is a delegate for String but not for the inline class wrapper. We'd need to take this into consideration.