NAPPS-1102 Add fee to swap transaction validation

[joaoccmartins]

Checklist

• App update process has been followed
• Target branch is develop
• Application version has been bumped

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 49.89%. Comparing base (02d07f3) to head (0c49c79).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop      #24   +/-   ##
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  Coverage    49.89%   49.89%           
========================================
  Files            8        8           
  Lines          483      483           
  Branches       120      120           
========================================
  Hits           241      241           
  Misses         242      242           

Flag	Coverage Δ
unittests	49.89% <ø> (ø)

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[joaoccmartins]

@bboilot-ledger changes to the validation to support the fees, as request in the other PR.

Had to also update the Exchange app tests to validate that the fee was taken into account (PR here)
cc @fbeutin-ledger @may01