flow improvements

[Wip-Sama]

• When a flow name is too long, it should appear in the tooltip
• Broken node should be rechecked when the plugin situation changes / at start to ensure they're still broken
• Indicate optional and required fields in the node view
• If a node is missing a required field, highlight it as not ready with a slight accent and a tag
• If a node is missing a required field, the flows should be marked as broken since it cannot run properly