[Compiler plugin ] Support ColumnName annotation in extension properties codegen

[koperagen]

Before this PR this code would fail with "abc is not found in dataframe" at runtime. After, behavior will be aligned with KSP

@DataSchema
data class Record(
    @ColumnName("a")
    val abc: String,
)

fun box(): String {
    val df = dataFrameOf("a")(1).cast<Record>()
    df.abc
    return "OK"
}