Clustering / bulk_insert on a BINARY (bytes) sort column throws ClassCastException: [B cannot be cast to java.lang.Comparable

When clustering (or `bulk_insert`) sorts by a column of BINARY/bytes type on the Spark record path (`HoodieSparkRecord`), the job fails with:

```
java.lang.ClassCastException: [B cannot be cast to java.lang.Comparable
at org.apache.hudi.common.util.collection.FlatLists.ofComparableArray(FlatLists.java:55)
```

`SortUtils.getComparableSortColumns` builds the sort key by reading each sort column's value and passing it to `FlatLists.ofComparableArray`, which casts every element to `Comparable`. On the Spark record path a binary column's value is a raw `byte[]`, which is not `Comparable`, so the cast throws and every clustering / bulk-insert attempt on that column fails.

The Avro record path does not hit this: `HoodieAvroUtils.getNestedFieldVal` returns a `java.nio.ByteBuffer` (which is `Comparable`) for the same column.

### Expected
A BINARY sort column should be usable as a clustering / bulk-insert sort key, ordered consistently with the Avro path.

### Environment
Hudi 1.x (master), Spark record type.