fix(api): bug in updated promotion endpoints

[krancour]

I overlooked that freightName can now be empty if the client provided freightAlias instead.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 30.15%. Comparing base (87ac85e) to head (4ce6340).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1575   +/-   ##
=======================================
  Coverage   30.15%   30.15%           
=======================================
  Files         185      185           
  Lines       20034    20034           
=======================================
  Hits         6041     6041           
  Misses      13718    13718           
  Partials      275      275           

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