bug/1881 handle bad journey retrieve-by-key responses gracefully

[JoernBerkefeld]

PR details

What changes did you make? (Give an overview)

• closes [BUG] gracefully handle journey-key-not-found #1881

Further details (optional)

...

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• test scripts updated
• Wiki updated (if applicable)

[github-actions]

Coverage Report

Commit:768de08
Base: develop@15293dc

Type	Base	This PR
Total Statements Coverage	69.72%	69.72%  (+0%)
Total Branches Coverage	69.01%	69.01%  (+0%)
Total Functions Coverage	81.87%	81.87%  (+0%)
Total Lines Coverage	69.72%	69.72%  (+0%)

Details (changed files):

File	Statements	Branches	Functions	Lines
lib/metadataTypes/Journey.js	59.01%	59.44%	76.19%	59.01%