Fix #3406, add logging of unexpected clipboard state

[ianb]

This logs cases when the passed-in text is empty, or the textarea select doesn't appear to work. Logs are sent to Sentry.

[codecov-io]

Codecov Report

Merging #3430 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3430   +/-   ##
=======================================
  Coverage   52.28%   52.28%           
=======================================
  Files          25       25           
  Lines        1425     1425           
  Branches      260      260           
=======================================
  Hits          745      745           
  Misses        680      680

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