Ensure all the empty arrays return an empty slice

[RiccardoM]

Description

Works towards #4741

Checklist

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.
• Wrote tests
• Updated relevant documentation (docs/)
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the github PR explorer

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For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #5248 into master will decrease coverage by 0.04%.
The diff coverage is 38.88%.

@@            Coverage Diff            @@
##           master   #5248      +/-   ##
=========================================
- Coverage   53.54%   53.5%   -0.05%     
=========================================
  Files         290     290              
  Lines       17738   17770      +32     
=========================================
+ Hits         9497    9507      +10     
- Misses       7502    7513      +11     
- Partials      739     750      +11

[alessio]

This should be marked as an API/ABI breaking change due to the changes in publicly exported functions return values

[alexanderbez]

Thanks @RiccardoM! Looks good apart from one change.

[alexanderbez]

ACK 🎉