fix: capture message in ApiError.stack

[legraphista]

Fixes #465

• Tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Note:

• automated tests may fail because of fix: undefined headers breaks compatibility with auth teeny-request#66

[legraphista]

Any update on this?
Our error reporting system (https://sentry.io) uses Error.stack as its primary source of information.
Most of our GCP related errors just state:

Error: 
    at Http2CallStream.<anonymous> ([REDACTED]/node_modules/google-gax/node_modules/@grpc/grpc-js/build/src/client.js:96:45)
    at Http2CallStream.emit (events.js:214:15)
    at Http2CallStream.EventEmitter.emit (domain.js:476:20)
    at [REDACTED]

[codecov]

Codecov Report

Merging #466 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #466      +/-   ##
==========================================
+ Coverage   98.29%   98.29%   +<.01%     
==========================================
  Files           5        5              
  Lines         410      411       +1     
  Branches      101      101              
==========================================
+ Hits          403      404       +1     
  Misses          2        2              
  Partials        5        5

Impacted Files	Coverage Δ
src/util.ts	98.07% <100%> (ø)	⬆️

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