Before this commit we were not benchmarking ksql with the
"omit-select" feature.
This could lead people to say that this feature is actually
expensive, but it really isn't so I just updated the benchmarks
to always run with this feature.
Before doing this change I actually put both features together
on the benchmark to compare them and these are the results:
```
ksql/sql-adapter/single-row-12 17186 143286 ns/op
ksql/sql-adapter-with-omit/single-row-12 16502 142893 ns/op
ksql/sql-adapter/multiple-rows-12 15361 153890 ns/op
ksql/sql-adapter-with-omit/multiple-rows-12 15360 156075 ns/op
ksql/pgx-adapter/single-row-12 33894 68332 ns/op
ksql/pgx-adapter-with-omit/single-row-12 34563 68861 ns/op
ksql/pgx-adapter/multiple-rows-12 29677 79196 ns/op
ksql/pgx-adapter-with-omit/multiple-rows-12 28934 80422 ns/op
```
Please note that benchmarks usually run slighly slower or faster
on each attempt, so small differences like the ones presented
above are really hard to interpret.