Small aggregation changes and test speedup

[andyleiserson]

• Remove some unnecessary IntoIterator bounds on Chunk methods.
• Add a Chunk::map helper to transform chunk data without extracting it from the wrapper. Use this instead of the somewhat confusing into_raw method. A side effect of this change is we no longer aggregate extra zero rows in the last block, which improves performance on small inputs.
• To further speed up protocol::ipa_prf::tests::semi_honest, switch it to 5-bit breakdown keys and 8-bit histogram values.
• Add a check that the BK and B parameters are consistent.
• Move type aliases from protocol to cli/playbook/ipa. Fixes #1079.

[codecov[bot]]

Codecov Report

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

Project coverage is 90.87%. Comparing base (798f679) to head (f8e625c).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1080 +/- ## ======================================= Coverage 90.87% 90.87% ======================================= Files 183 183 Lines 25691 25703 +12 ======================================= + Hits 23347 23358 +11 - Misses 2344 2345 +1 ```

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