Add tests

tests/queries/0_stateless/03000_virtual_columns_in_prewhere.reference

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tests/queries/0_stateless/03000_virtual_columns_in_prewhere.sql

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+drop table if exists x;
+
+create table x (i int, j int, k int) engine MergeTree order by tuple() settings index_granularity=8192, min_bytes_for_wide_part=0, min_rows_for_wide_part=0;
+
+insert into x select number, number * 2, number * 3 from numbers(100000);
+
+-- One granule, (_part_offset (8 bytes) + <one minimal physical column> (4 bytes)) * 8192 + <other two physical columns>(8 bytes) * 1 = 98312
+select * from x prewhere _part_offset = 0 settings max_bytes_to_read = 98312;
+
+drop table x;