`RepartitionExec` is missing `BaselineMetrics`

### Is your feature request related to a problem or challenge?

`BaselineMetrics` is a set of common metrics for almost all operators, now `RepartitionExec` is not tracking it.

The `BaselineMetrics` `output_rows` and `elapsed_compute` are not showed in `RepartitionExec` in the below `datafusion-cli` reproducer:
```
> explain analyze
select v1, count(*)
from generate_series(1,100) as t1(v1)
group by v1;
+-------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| plan_type | plan |
+-------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Plan with Metrics | ProjectionExec: expr=[v1@0 as v1, count(Int64(1))@1 as count(*)], metrics=[output_rows=100, elapsed_compute=9.332µs] |
| | AggregateExec: mode=FinalPartitioned, gby=[v1@0 as v1], aggr=[count(Int64(1))], metrics=[output_rows=100, elapsed_compute=4.043955ms, spill_count=0, spilled_bytes=0.0 B, spilled_rows=0, peak_mem_used=67328] |
| | CoalesceBatchesExec: target_batch_size=8192, metrics=[output_rows=100, elapsed_compute=60.834µs] |
| | RepartitionExec: partitioning=Hash([v1@0], 14), input_partitions=14, metrics=[fetch_time=7.515374ms, repartition_time=45.428µs, send_time=14.348µs] |
| | AggregateExec: mode=Partial, gby=[v1@0 as v1], aggr=[count(Int64(1))], metrics=[output_rows=100, elapsed_compute=5.612461ms, spill_count=0, spilled_bytes=0.0 B, spilled_rows=0, skipped_aggregation_rows=0, peak_mem_used=7328] |
| | RepartitionExec: partitioning=RoundRobinBatch(14), input_partitions=1, metrics=[fetch_time=17.459µs, repartition_time=1ns, send_time=11.471µs] |
| | ProjectionExec: expr=[value@0 as v1], metrics=[output_rows=100, elapsed_compute=1.667µs] |
| | LazyMemoryExec: partitions=1, batch_generators=[generate_series: start=1, end=100, batch_size=8192], metrics=[output_rows=100, elapsed_compute=10.458µs] |
| | |
+-------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row(s) fetched.
Elapsed 0.011 seconds.
```

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start by locating the RepartitionExec implementation and how BaselineMetrics is used by the other operators. Reproduce the issue with the provided datafusion-cli EXPLAIN ANALYZE query, then verify that RepartitionExec reports output_rows and elapsed_compute alongside its existing metrics.

Written by the indexing model from the issue text.