Jupyter importDataSchema() does not generate column accessors

[Jolanrensen]

Jupyter importDataSchema() does not generate column accessors. This is likely due to nested @DataSchema interfaces being skipped:

%trackExecution
@DataSchema
interface A {
    val a: Int
}

interface B {
    @DataSchema
    interface C {
        val c: Int
    }
}

Executing:

val ColumnsContainer<Line_22_jupyter.A>.a: DataColumn<Int> @JvmName("A_a") get() = this["a"] as DataColumn<Int>
val DataRow<Line_22_jupyter.A>.a: Int @JvmName("A_a") get() = this["a"] as Int
val ColumnsContainer<Line_22_jupyter.A?>.a: DataColumn<Int?> @JvmName("NullableA_a") get() = this["a"] as DataColumn<Int?>
val DataRow<Line_22_jupyter.A?>.a: Int? @JvmName("NullableA_a") get() = this["a"] as Int?

[Jolanrensen]

Dependent on: https://youtrack.jetbrains.com/issue/KTNB-680/ClassAnnotationHandler-does-not-handle-nested-interfaces-classes

[Jolanrensen]

After #700 is solved, this should be as well, I'll check up on it quickly