Improve synthetic data generation

[jmbhughes]

• switches to prefect-dask for parallelism
• sqrt encodes level 0 data
• re-enables database population

Resolves #69

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (583c6dc) to head (4fd6ddc). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #71 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 3 3 Lines 48 48 ========================================= Hits 48 48 ```

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