feat(rust,python): Faster bitpacking for Parquet writer

[thalassemia]

I replaced the Parquet bit-packing algorithm with a modified version of the scalar algorithm from https://github.com/quickwit-oss/bitpacking (unsure where/how to give credit). I ensured the new algorithm works by adding unit tests that encode/decode random data.

I added a microbenchmark in my first commit to help measure the performance gain.

	Before	After
Avg. (ns/iter)	93.75	4.25
Std. (ns/iter)	1.57	0.04

I removed the microbenchmark in a later commit because it requires nightly Rust and is probably not useful outside of this PR.

Other miscellaneous fixes:

• Packed array of 64 u64's should have a maximum length of 64 * 8 u8's (second commit)
• Input array length should be compared to expected unpacked length instead of expected packed length to avoid unnecessary allocations/copies (third commit)

[codecov[bot]]

Codecov Report

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

Project coverage is 81.34%. Comparing base (11fe9d8) to head (b8ff88d). Report is 18 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16278      +/-   ##
==========================================
+ Coverage   80.80%   81.34%   +0.53%     
==========================================
  Files        1393     1403      +10     
  Lines      179406   183257    +3851     
  Branches     2921     2922       +1     
==========================================
+ Hits       144971   149063    +4092     
+ Misses      33932    33691     -241     
  Partials      503      503              

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[ritchie46]

Nice improvement! Thanks a lot @thalassemia. :raised_hands: Hope you find some on the reading side as well. ;)