Fix json encoding for transaction result

[ryokik]

Closes #1715

Description

Fixed the issue where an empty string was returned when using flow transaction get with the -o json option.

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For contributor use:

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 29.68%. Comparing base (f99a061) to head (ecc8619).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1768   +/-   ##
=======================================
  Coverage   29.68%   29.68%           
=======================================
  Files          89       89           
  Lines        5191     5191           
=======================================
  Hits         1541     1541           
  Misses       3463     3463           
  Partials      187      187           

Flag	Coverage Δ
unittests	29.68% <100.00%> (ø)

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[jribbink]

Thanks for the contribution! Will review today 🫡

[jribbink]

Nice, thank you! Must have broken at some point as event encoding changed to CCF :)