ARROW-5112: [Go] implement writing IPC Arrow stream/file

[sbinet]

Needs #4228.

[sbinet]

PTAL @stuartcarnie @alexandreyc @nickpoorman

[nickpoorman]

LGTM

[stuartcarnie]

It is a large PR, so I was looking though the commits for tests. I don't have a sense of the amount of coverage but I do see lots of tests.

LGTM 🎉

[sbinet]

yeah... I don't know why the code coverage app didn't post its report...
I'll try to post mine in the coming days.

[codecov-io]

Codecov Report

Merging #4229 into master will decrease coverage by 16.44%.
The diff coverage is 68.46%.

@@             Coverage Diff             @@
##           master    #4229       +/-   ##
===========================================
- Coverage   88.27%   71.83%   -16.45%     
===========================================
  Files         763       71      -692     
  Lines       93723     5943    -87780     
  Branches     1251        0     -1251     
===========================================
- Hits        82735     4269    -78466     
+ Misses      10875     1446     -9429     
- Partials      113      228      +115

Impacted Files	Coverage Δ
go/arrow/internal/bitutil/bitutil.go	90.32% <0%> (-3.02%)	⬇️
go/arrow/array/struct.go	81.13% <0%> (-3.19%)	⬇️
go/arrow/array/binary.go	62.74% <0%> (-21.47%)	⬇️
go/arrow/array/list.go	72.64% <0%> (-1.92%)	⬇️
go/arrow/ipc/ipc.go	75% <100%> (+75%)	⬆️
go/arrow/ipc/file_reader.go	58.14% <40%> (+58.14%)	⬆️
go/arrow/array/string.go	74.6% <50%> (-1.21%)	⬇️
go/arrow/ipc/reader.go	55.22% <50%> (+55.22%)	⬆️
go/arrow/ipc/metadata.go	63.58% <67.91%> (+63.58%)	⬆️
go/arrow/ipc/file_writer.go	69.03% <69.03%> (ø)
... and 706 more

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