fix(ui): workflow edges not saved

[psychedelicious]

Summary

• fix(ui): ensure invocation edges have a type

• fix(ui): store hidden state of edges in workflows

  This prevents a minor visual bug where collapsed edges between collapsed nodes didn't display correctly on first load of a workflow.

Related Issues / Discussions

https://discord.com/channels/1020123559063990373/1149513625321603162/1241849984140447886

QA Instructions

• Save and then load a workflow, its edges should be saved.
• Collapse two connected nodes so their edges are in the collapsed state. Save and load the workflow, the collapsed edge state should be retained (e.g. grey line w/ a number over it if there were multiple edges).

Merge Plan

n/a

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• Documentation added / updated (if applicable)