Drop columns only allows unqualified names and silently fails otherwise

[ntjohnson1]

Describe the bug

If we try to drop a column using drop_columns but with a qualified name table.col then it doesn't match and silently skips the attempt to drop the column. See repro below where I'd expect the plans to match.

To Reproduce

let mut t = test_table().await?;
t = t.select_columns(&["c1", "c2", "c11"])?;
let mut t2 = test_table_with_name("another_table").await?;
t2 = t2.select_columns(&["c1", "c2", "c11"])?;
let mut t3 = t.join_on(
   t2,
   JoinType::Inner,
   [col("aggregate_test_100.c1").eq(col("another_table.c1"))],
)?;
t3 = t3.drop_columns(&["another_table.c2", "another_table.c11"])?;

let plan = t3.logical_plan().clone();

let sql = "SELECT aggregate_test_100.c1, aggregate_test_100.c2, aggregate_test_100.c11, another_table.c1  FROM (SELECT c1, c2, c11 FROM aggregate_test_100) INNER JOIN (SELECT c1, c2, c11 FROM another_table) ON aggregate_test_100.c1 = another_table.c1";
let ctx = SessionContext::new();
register_aggregate_csv(&ctx, "aggregate_test_100").await?;
register_aggregate_csv(&ctx, "another_table").await?;
let sql_plan = ctx.sql(sql).await?.into_unoptimized_plan();

Expected behavior

The sql plans match. Or (less nice) the documentation mentions this limitation and there is an error.

Additional context

No response