Fix varbinary display to show hex format with 0x prefix

Modified StringType.SQL method to format binary data as hexadecimal with 0x prefix
to match MySQL's behavior when displaying binary data in CLI results.

Fixes dolthub/dolt#9554

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: elianddb

sql/types/strings.go

@@ -712,7 +712,7 @@ func (t StringType) SQL(ctx *sql.Context, dest []byte, v interface{}) (sqltypes.
 			return sqltypes.Value{}, err
 		}
 
-		// Format binary data in the MySQL CLI format, which is 0x followed by hex digits
+		// Format binary data as hexadecimal with 0x prefix to match MySQL's display behavior
 		result := append([]byte("0x"), bytes.ToUpper([]byte(fmt.Sprintf("%x", binaryBytes)))...)
 		val = result
 	} else {

sql/types/strings_test.go

@@ -379,7 +379,7 @@ func TestStringConvert(t *testing.T) {
 	}
 }
 
-func TestStringSQL(t *testing.T) {
+func TestBinaryDataSQLFormatting(t *testing.T) {
 	ctx := sql.NewEmptyContext()
 	tests := []struct {
 		name        string