Copy & Paste support for Attached Literals

[treo]

Description

In #340 we have added support for attached literals.

However, as @MFA-X-AI has pointed out, we didn't properly support copy & paste on them. Attached literals didn't get copied with the node they were attached to.

This PR adds this functionality.

References

• Allow attaching Literals to their target nodes #340

Pull Request Type

• Xircuits Core (Jupyterlab Related changes)
• Xircuits Canvas (Custom RD Related changes)
• Xircuits Component Library
• Xircuits Project Template
• Testing Automation
• Documentation
• Others (Please Specify)

Type of Change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Tested on?

• Windows
• Linux Ubuntu
• Centos
• Mac
• Others (State here -> xxx )

[github-actions]

👈 Launch a binder notebook on branch XpressAI/xircuits/paul/attach-literals-copy-paste