Add PiecewiseSequence take microbenchmarks

[danking]

@robert3005 I'm not sure if you want to check these in. These are what I used to reason about various ways to copy slices of data from one spot in memory to another.

Summary

• add piecewise_sequence_take_primitive to compare constant-length PiecewiseSequence take against dense lengths and reifying constant lengths
• add take_slices_to_buffer_matrix to compare extend/cursor-copy loops with and without preverification plus unchecked slicing

Validation

• cargo +nightly fmt --all
• cargo clippy -p vortex-array --all-targets --all-features -- -D warnings
• cargo bench -p vortex-array --bench piecewise_sequence_take_primitive
• cargo bench -p vortex-array --bench take_slices_to_buffer_matrix

[robert3005]

I think we want benchmarks. I came up with the long term solution in #8825 and we have to make sure we don't regress