Preserve spacing when merging flow style YAML

[BelmoMusta]

What's changed?

Fixing the unwanted carriage return when merging yaml values that are written in flow style

What's your motivation?

• Resolves Style not preserved with MergeYaml when values are written in flow style #4958

Anything in particular you'd like reviewers to focus on?

Anyone you would like to review specifically?

Have you considered any alternatives or workarounds?

Any additional context

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[timtebeek]

Thanks a lot @BelmoMusta ; should help improve the cases where folks use that flow style.