Fix an inconsistency in MapObjectEncoder

[NWilson]

For some reason, ObjectEncoder has AddBinary and AddByteString methods, but ArrayEncoder only has AppendByteString. This PR adds the missing (forgotten?) AppendBinary method.

Also, I've fixed up a small inconsistency in the MapObjectEncoder that's used in the tests.

Two independent commits - can be reviewed/merged separately (or split into two PRs if you prefer).

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #657 into master will increase coverage by 0.04%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #657      +/-   ##
==========================================
+ Coverage   97.38%   97.43%   +0.04%     
==========================================
  Files          40       40              
  Lines        2102     2102              
==========================================
+ Hits         2047     2048       +1     
+ Misses         47       46       -1     
  Partials        8        8

Impacted Files	Coverage Δ
zapcore/memory_encoder.go	100% <100%> (+1.33%)	⬆️

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[akshayjshah]

Thank you for opening this PR! It's been a while since we wrote this code, so I'm honestly not sure why there's no AppendByteString on the PrimitiveArrayEncoder interface. It was probably an oversight - good on you for catching it!

Unfortunately, we can't add this method today, since it breaks backward compatibility. (Adding a method to an interface immediately breaks all third-party implementations of that interface.) I don't want to forget about this, though, so can you please add an item to #388? If we ever accumulate enough changes that we're ready to cut a v2, we'll fix this oversight too.

That said, I would love to pull in your fix to the in-memory encoder. Can you drop the second commit on this PR and fix up the description?

[akshayjshah]

Also, thank you for pitching in to help answer issues. It's immensely helpful.

[NWilson]

Sorry for the long delay, I almost forgot about this! I've removed the ArrayEncoder changes, and put them in a separate PR.

Since you have various "v2" issues queued up, could you make a branch so that you can merge the PRs - and there's no rush to actually finish and release the v2 API.

[NWilson]

Ping - I made the changes requested, this PR now only contains the changes that are OK to merge to master.

[prashantv]

Looks good to me, thanks for the fix.