[SPARK-56332][SQL][TESTS] Use sql.SparkSession in trait SQLTestData

### What changes were proposed in this pull request?
Use `sql.SparkSession` in `trait SQLTestData`

### Why are the changes needed?
this is needed for merging SQLTestUtils and QueryTest

### Does this PR introduce _any_ user-facing change?
No, test-only

### How was this patch tested?
CI

### Was this patch authored or co-authored using generative AI tooling?
Co-authored-by: Claude code (Opus 4.6)

Closes #55162 from zhengruifeng/merge_sql_utils.

Authored-by: Ruifeng Zheng <ruifengz@apache.org>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

Author: zhengruifeng