### What changes were proposed in this pull request?
This pr push the `UnaryExpression` into (if / case) branches. The use case is:
```sql
create table t1 using parquet as select id from range(10);
explain select id from t1 where (CASE WHEN id = 1 THEN '1' WHEN id = 3 THEN '2' end) > 3;
```
Before this pr:
```
== Physical Plan ==
*(1) Filter (cast(CASE WHEN (id#1L = 1) THEN 1 WHEN (id#1L = 3) THEN 2 END as int) > 3)
+- *(1) ColumnarToRow
+- FileScan parquet default.t1[id#1L] Batched: true, DataFilters: [(cast(CASE WHEN (id#1L = 1) THEN 1 WHEN (id#1L = 3) THEN 2 END as int) > 3)], Format: Parquet, Location: InMemoryFileIndex[file:/Users/yumwang/opensource/spark/spark-warehouse/org.apache.spark.sql.DataF..., PartitionFilters: [], PushedFilters: [], ReadSchema: struct<id:bigint>
```
After this pr:
```
== Physical Plan ==
LocalTableScan <empty>, [id#1L]
```
This change can also improve this case:
a78d6ce376/sql/core/src/test/resources/tpcds/q62.sql (L5-L22)
### Why are the changes needed?
Improve query performance.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Unit test.
Closes#30853 from wangyum/SPARK-33848.
Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
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