Fix system event invocationFailed field name

[mthenw]

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification commands / resources
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: YES

[sebito91]

[codecov]

Codecov Report

Merging #487 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #487   +/-   ##
=======================================
  Coverage   70.77%   70.77%           
=======================================
  Files          37       37           
  Lines        2190     2190           
=======================================
  Hits         1550     1550           
  Misses        576      576           
  Partials       64       64

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