Unwrap executeActionReturning to return multiple

[easel]

Fixes #2254

Problem

.returning returns a single value instead of a list, failing on both zero and n > 1

Solution

Return a list instead of a scalar from executeActionReturning

Notes

Additional notes.

Checklist

• Unit test all changes
• Update README.md if applicable
• Add [WIP] to the pull request title if it's work in progress
• Squash commits that aren't meaningful changes
• Run sbt scalariformFormat test:scalariformFormat to make sure that the source files are formatted

@getquill/maintainers

[guizmaii]

@easel What's the status of your PR?