ARROW-4038: [Rust] Implement boolean AND, OR, NOT array ops

[andygrove]

• Implements boolean AND, OR, NOT operations in array_ops
• Removes all uses of unwrap() in array_ops and replaces with ?
• Improve error messages

[andygrove]

@paddyhoran @sunchao Could I get a review please. Rust tests are passing but Python tests failed with a timeout.

[sunchao]

Thanks @andygrove . It seems there is no well-established rules to define what's the result should be when one of the operand is null. Maybe we should add document for each public methods and clearly describe the behavior. This can be in a different PR of course.

Another minor thing is, in operators such as gt_eq, we define:

    bool_op(left, right, |a, b| match (a, b) {
        (None, _) => false,
        (_, None) => true,
        (Some(aa), Some(bb)) => aa >= bb,
    })

However this means None and None is also mapped to false, is that right? This perhaps is unexpected.

[codecov-io]

Codecov Report

Merging #3189 into master will increase coverage by 1.14%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3189      +/-   ##
==========================================
+ Coverage   86.41%   87.56%   +1.14%     
==========================================
  Files         504      450      -54     
  Lines       69587    66065    -3522     
==========================================
- Hits        60137    57853    -2284     
+ Misses       9353     8212    -1141     
+ Partials       97        0      -97

Impacted Files	Coverage Δ
cpp/src/arrow/compute/compute-test.cc	93.1% <0%> (-6.34%)	⬇️
python/pyarrow/feather.py	86.95% <0%> (-2.46%)	⬇️
cpp/src/arrow/python/helpers.cc	77.54% <0%> (-2.12%)	⬇️
python/pyarrow/tests/test_feather.py	96.7% <0%> (-1.16%)	⬇️
python/pyarrow/tests/conftest.py	73.91% <0%> (-0.78%)	⬇️
cpp/src/arrow/compute/kernels/cast.cc	91.47% <0%> (-0.4%)	⬇️
python/pyarrow/tests/test_convert_pandas.py	95.01% <0%> (-0.12%)	⬇️
cpp/src/parquet/arrow/reader.cc	84.72% <0%> (-0.11%)	⬇️
cpp/src/parquet/arrow/arrow-reader-writer-test.cc	95.92% <0%> (-0.04%)	⬇️
cpp/src/arrow/io/hdfs.cc	0.31% <0%> (-0.02%)	⬇️
... and 104 more

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[andygrove]

Thanks @sunchao I addressed your feedback. Good points.

[sunchao]

LGTM. Thanks @andygrove .