Add support for UnionArray infilter kernel

[viirya]

Which issue does this PR close?

Closes #1394.

Rationale for this change

What changes are included in this PR?

Are there any user-facing changes?

[viirya]

cc @alamb

[codecov-commenter]

Codecov Report

Merging #1412 (6caca96) into master (1fbe618) will increase coverage by 0.05%.
The diff coverage is 87.42%.

@@            Coverage Diff             @@
##           master    #1412      +/-   ##
==========================================
+ Coverage   83.13%   83.18%   +0.05%     
==========================================
  Files         182      183       +1     
  Lines       53321    53613     +292     
==========================================
+ Hits        44330    44600     +270     
- Misses       8991     9013      +22     

Impacted Files	Coverage Δ
arrow/src/array/data.rs	82.95% <54.54%> (-0.21%)	⬇️
arrow/src/array/transform/union.rs	75.00% <75.00%> (ø)
arrow/src/array/transform/mod.rs	86.29% <84.61%> (-0.03%)	⬇️
arrow/src/compute/kernels/filter.rs	87.22% <100.00%> (+1.82%)	⬆️
arrow/src/datatypes/datatype.rs	66.40% <0.00%> (-0.40%)	⬇️
parquet_derive/src/parquet_field.rs	65.98% <0.00%> (-0.23%)	⬇️
parquet/src/encodings/encoding.rs	93.52% <0.00%> (-0.20%)	⬇️
arrow/src/array/ffi.rs	100.00% <0.00%> (ø)
arrow-flight/src/utils.rs	0.00% <0.00%> (ø)
... and 6 more

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[alamb]

Sorry I have been a bit backed up for arrow reviews. Checking this one out now

[viirya]

Thank you @alamb !