[SPARK-47703][SQL] Modify the simpleString of DataSourceV2ScanRelation to distinguish it from DataSourceV2Relation

[Zouxxyy]

What changes were proposed in this pull request?

Modify the simpleString of DataSourceV2ScanRelation to distinguish it from DataSourceV2Relation

Why are the changes needed?

At present, the simpleString of DataSourveV2ScanRelation and DataSourveV2Relation are the same, it is difficult to distinguish them.

before:

=== Applying Rule org.apache.spark.sql.execution.datasources.v2.V2ScanRelationPushDown ===
 Subquery true                                                                                                                                 Subquery true
!+- RelationV2[cs_sold_date_sk#116L, cs_sold_time_sk#117L, cs_ship_date_sk#118L, cs_bill_customer_sk#119L, ... 30 more fields] catalog_sales   +- RelationV2[cs_sold_date_sk#116L, cs_sold_time_sk#117L, cs_ship_date_sk#118L, cs_bill_customer_sk#119L, ... 30 more fields] catalog_sales
 

after:

=== Applying Rule org.apache.spark.sql.execution.datasources.v2.V2ScanRelationPushDown ===
 Subquery true                                                                                                                                 Subquery true
!+- RelationV2[cs_sold_date_sk#116L, cs_sold_time_sk#117L, cs_ship_date_sk#118L, cs_bill_customer_sk#119L, ... 30 more fields] catalog_sales   +- ScanRelationV2[cs_sold_date_sk#116L, cs_sold_time_sk#117L, cs_ship_date_sk#118L, cs_bill_customer_sk#119L, ... 30 more fields] catalog_sales
 

Does this PR introduce any user-facing change?

How was this patch tested?

Was this patch authored or co-authored using generative AI tooling?

[HyukjinKwon]

what's diff between before and after?

[Zouxxyy]

V2ScanRelationPushDown

before:
after apply V2ScanRelationPushDown, RelationV2 -> RelationV2, we don't know if this rule works

after:
RelationV2 -> ScanRelationV2

[HyukjinKwon]

That's not how it's written in the PR description :-).

[Zouxxyy]

That's not how it's written in the PR description :-).

Oh, this is the standard log of spark.sql.planChangeLog.rules, you need to slide it