feat(spanner): add option for DataBoost

[olavloite]

Adds an option to use DataBoost with partitioned queries and partitioned reads.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.73%. Comparing base (6da623f) to head (8783dd1).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5447      +/-   ##
==========================================
- Coverage   97.73%   97.73%   -0.01%     
==========================================
  Files         217      217              
  Lines       48186    48243      +57     
==========================================
+ Hits        47096    47151      +55     
- Misses       1090     1092       +2     

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[dbolduc]

We tend to use builders so applications don't have to supply default options everywhere.

Maybe like p.execute(&db_client).set_data_boost(true).send().await

Thoughts?

[olavloite]

Fair point. However, our other execute(..) methods all really execute the statement, and I would prefer this method to be consistent with that pattern. So I've changed this so that Partition has a with_data_boost method (and could also hold more options in the future if needed). The call then looks like this:

    let mut result_set = partitions[0].clone()
        .with_data_boost(true)
        .execute(&db_client)
        .await?;