[SPARK-39893][SQL] Push limit 1 to the aggregate's child plan if grouping expressions and aggregate expressions are foldable

[wankunde]

What changes were proposed in this pull request?

If all group expressions are foldable, the result of this aggregate will always be OneRowRelation. And if all aggregate expressions are foldable, we can add limit 1 to the child plan.

For example:

Table tab (it can have data or empty) : create table tab(key int, value string) using parquet Query : SELECT distinct 1001 as id , cast('2022-06-03' as date) AS DT FROM tab

After this PR:

=== Applying Rule org.apache.spark.sql.catalyst.optimizer.LimitPushDown ===
 Aggregate [1001, 2022-06-03], [1001 AS id#218, 2022-06-03 AS DT#219]   Aggregate [1001, 2022-06-03], [1001 AS id#218, 2022-06-03 AS DT#219]
!+- Project [1001 AS id#218, 2022-06-03 AS DT#219]                      +- GlobalLimit 1
!   +- Relation spark_catalog.default.tab[key#220,value#221] parquet       +- LocalLimit 1
!                                                                             +- Project [1001 AS id#218, 2022-06-03 AS DT#219]
!                                                                                +- Relation spark_catalog.default.tab[key#220,value#221] parquet

Query: SELECT 1001 AS id, cast('2022-06-03' as date) AS DT FROM tab group by 'x'

=== Applying Rule org.apache.spark.sql.catalyst.optimizer.LimitPushDown ===
 Aggregate [0], [1001 AS id#218, cast(2022-06-03 as date) AS DT#219]   Aggregate [0], [1001 AS id#218, cast(2022-06-03 as date) AS DT#219]
!+- Relation spark_catalog.default.tab[key#220,value#221] parquet      +- GlobalLimit 1
!                                                                         +- LocalLimit 1
!                                                                            +- Relation spark_catalog.default.tab[key#220,value#221] parquet
 

Why are the changes needed?

Push limit 1 to child plan to reduce unnecessary calculations

Does this PR introduce any user-facing change?

No

How was this patch tested?

Add UT

[AmplabJenkins]

Can one of the admins verify this patch?

[github-actions[bot]]

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