Group by duplicate GROUPING SETS returns wrong result

**Describe the bug**

**To Reproduce**

```rust
let sql = "SELECT c1, avg(c12) FROM aggregate_test_100 GROUP BY GROUPING SETS((c1),(c1),())";
let actual = execute_to_batches(&ctx, sql).await;
let expected = vec![
"+----+-----------------------------+",
"| c1 | AVG(aggregate_test_100.c12) |",
"+----+-----------------------------+",
"| | 0.5089725099127211 |",
"| a | 0.48754517466109415 |",
"| b | 0.41040709263815384 |",
"| c | 0.6600456536439784 |",
"| d | 0.48855379387549824 |",
"| e | 0.48600669271341534 |",
"| a | 0.48754517466109415 |",
"| b | 0.41040709263815384 |",
"| c | 0.6600456536439784 |",
"| d | 0.48855379387549824 |",
"| e | 0.48600669271341534 |",
"+----+-----------------------------+",
];

```

the actual returned is:

```rust

"+----+-----------------------------+",
"| c1 | AVG(aggregate_test_100.c12) |",
"+----+-----------------------------+",
"| | 0.5089725099127211 |",
"| a | 0.48754517466109415 |",
"| b | 0.41040709263815384 |",
"| c | 0.6600456536439784 |",
"| d | 0.48855379387549824 |",
"| e | 0.48600669271341534 |",
"+----+-----------------------------+",
```

**Expected behavior**

**Additional context**

Start by reproducing the reported query through the Rust execute_to_batches(&ctx, sql) entry point and compare its batches with the expected output. Trace the GROUPING SETS handling and add or update coverage for GROUPING SETS((c1),(c1),()); done means both occurrences of the grouped rows are returned along with the empty grouping set.

Written by the indexing model from the issue text.