workflow builder iteration 2

[psychedelicious]

Summary

• Give image fields a max height and show the image dimensions in a badge.
• Make the field name the drag handle for fields. Previously it was the whole field name "bar", and it was really easy to accidentally drag a field when you wanted to drag a node.
• Abstract out node and field validation logic (i.e. when a field is required but doesn't have value). Previously this was awkwardly duplicated.
• Take advantage of the restructured field validation logic to make node titles error-colored when any field has is invalid (this was not possible w/ the prev code structure).
• Fix an issue where pasting nodes/edges that include a collapsed edge failed.
• Double-clicking a node fits it to view. Some care is required for this to not interfere with other click-activated functionality (editable titles, buttons, input fields).

Related Issues / Discussions

Offline discussion

QA Instructions

Try it out

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)
• Updated What's New copy (if doing a release after this PR)