Convert LazyBodyNode to real ones before performing (deep)Copy

[hubertp]

[ci no changelog needed]

Pull Request Description

Patch provided by Jaroslav, appears to fix local issues with inifite loop
introduced in #3429.
Fairly urgent since this issue currently blocks people.

Important Notes

This renders #3439 obsolete. Related to https://www.pivotaltracker.com/n/projects/2539304/stories/182024911

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the Scala, Java, and Rust style guides.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed: Enso GUI was tested when built using BOTH ./run dist and ./run watch.

[radeusgd]

While we should probably proceed with this ASAP to avoid blocking, I think we should investigate why it kept working on the CI, given that all (?) of us were able to reproduce this locally - and if we can do something to make sure that such issues are not overlooked by the CI.

[jdunkerley]

Absolutely agree with @radeusgd point we should understand why CI didn't show this issue