Fix output edges; add unit and integration testing.

Fix output edges; add unit and integration testing for output and input edges.

Fixes #11635.

Please ensure that the following checklist has been satisfied before submitting the PR:

[x] The documentation has been updated, if necessary.
[x] Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
[x] All code follows the Scala, Java, TypeScript, and Rust style guides. In case you are using a language not listed above, follow the Rust style guide.
[x] Unit tests have been written where possible.
[x] If meaningful changes were made to logic or tests affecting Enso Cloud integration in the libraries, or the Snowflake database integration, a run of the Extra Tests has been scheduled.
- If applicable, it is suggested to paste a link to a successful run of the Extra Tests.

enso-org / enso