Implement Into<ArrayData> for T: Array

[heyrutvik]

Which issue does this PR close?

Closes #1979

Rationale for this change

The method into_data is a cheaper alternative to the more pervasive .data().clone() calls to get underlying array data. It's cheaper since it doesn't clone anything but returns already allocated data (except for ArrayRef).

What changes are included in this PR?

It implements Into indirectly to convert specific array type to general one.

Are there any user-facing changes?

It adds fn into_data(self) -> ArrayData method to Array trait.

[codecov-commenter]

Codecov Report

Merging #1992 (f3e0768) into master (7ae97c9) will decrease coverage by 0.00%.
The diff coverage is 89.14%.

@@            Coverage Diff             @@
##           master    #1992      +/-   ##
==========================================
- Coverage   83.58%   83.57%   -0.01%     
==========================================
  Files         222      222              
  Lines       57495    57542      +47     
==========================================
+ Hits        48056    48090      +34     
- Misses       9439     9452      +13     

Impacted Files	Coverage Δ
arrow/src/array/array_decimal.rs	92.88% <0.00%> (-0.79%)	⬇️
.../src/array/builder/primitive_dictionary_builder.rs	78.68% <ø> (ø)
integration-testing/src/lib.rs	0.00% <0.00%> (ø)
arrow/src/array/array_union.rs	90.14% <20.00%> (-0.78%)	⬇️
arrow/src/array/array_map.rs	83.07% <55.55%> (-1.74%)	⬇️
arrow/src/json/reader.rs	84.58% <77.77%> (ø)
arrow/src/array/array.rs	92.05% <83.33%> (-0.16%)	⬇️
arrow/src/array/array_binary.rs	94.29% <100.00%> (+0.08%)	⬆️
arrow/src/array/array_boolean.rs	93.38% <100.00%> (+0.20%)	⬆️
arrow/src/array/array_dictionary.rs	92.06% <100.00%> (+0.12%)	⬆️
... and 25 more

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[tustvold]

LGTM, thank you 😀

[tustvold]

I'm going to say this isn't a breaking change, as whilst technically Array can be implemented outside this crate, practically the use of as_any means it can't be

[alamb]

Thanks @heyrutvik