Use initial capacity for interner hashmap

[Dandandan]

Which issue does this PR close?

Closes #2273 2273

Rationale for this change

This saves rehashing / reshuffling the hashmap when there are quite some distinct values.

This is quite a bit faster:

 Benchmarking write_batch primitive/4096 values primitive:
                        time:   [1.0495 ms 1.0520 ms 1.0550 ms]
                        thrpt:  [167.22 MiB/s 167.70 MiB/s 168.09 MiB/s]
                 change:
                        time:   [-24.025% -22.929% -21.823%] (p = 0.00 < 0.05)
                        thrpt:  [+27.916% +29.751% +31.622%]
                        Performance has improved.
Benchmarking write_batch primitive/4096 values primitive non-null:     
                        time:   [826.87 µs 827.46 µs 828.10 µs]
                        thrpt:  [208.91 MiB/s 209.07 MiB/s 209.22 MiB/s]
                 change:
                        time:   [-36.274% -36.156% -36.056%] (p = 0.00 < 0.05)
                        thrpt:  [+56.388% +56.633% +56.922%]
                        Performance has improved.

What changes are included in this PR?

Adds an initial capacity for the hashmap.

Are there any user-facing changes?

[tustvold]

Nice 👍

[codecov-commenter]

Codecov Report

Merging #2272 (a2c8f0a) into master (d4f038a) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2272      +/-   ##
==========================================
- Coverage   82.28%   82.28%   -0.01%     
==========================================
  Files         245      245              
  Lines       62688    62688              
==========================================
- Hits        51583    51582       -1     
- Misses      11105    11106       +1     

Impacted Files	Coverage Δ
parquet/src/util/interner.rs	91.66% <100.00%> (ø)
...rquet/src/arrow/record_reader/definition_levels.rs	87.34% <0.00%> (-1.69%)	⬇️
parquet/src/arrow/schema.rs	96.76% <0.00%> (-0.18%)	⬇️
arrow/src/datatypes/datatype.rs	62.61% <0.00%> (+0.31%)	⬆️
parquet_derive/src/parquet_field.rs	66.21% <0.00%> (+0.68%)	⬆️

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[ursabot]

Benchmark runs are scheduled for baseline = d4f038a and contender = b4fa47d. b4fa47d is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java