Fix publish_outcomes and publish_errors_total metrics

[renaz6]

Fixes https://github.com/comcast-cl/xmidt/issues/5734
and possibly https://github.com/comcast-cl/xmidt/issues/5736

• Adds outcome.String() to the log statement so the string value of the outcome is logged, not just the corresponding iota constant
• Adds a metric notifier for publish_errors_total when the publisher receives an error from attempting to produce a message
• Moves the metric notifier for publish_outcomes before the handleOutcome call (could the handleOutcome call be cancelling the context before the metric is updated?)

[codecov]

Codecov Report

❌ Patch coverage is 30.00000% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.89%. Comparing base (093dcc3) to head (840f15b).

Files with missing lines	Patch %	Lines
internal/publisher/publisher.go	12.50%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #97      +/-   ##
==========================================
- Coverage   81.22%   80.89%   -0.33%     
==========================================
  Files          30       30              
  Lines        1731     1738       +7     
==========================================
  Hits         1406     1406              
- Misses        296      303       +7     
  Partials       29       29              

Flag	Coverage Δ
unittests	80.89% <30.00%> (-0.33%)	⬇️

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