Flow editor improvements

[keller-mark]

• handle/figure out how to represent undefined view-scope mappings for supported coordination types
• implement better isValidConnection using viewTypes and list of supported coordinationTypes per viewType (and mapping between viewUids and viewTypes)
• <select> in view nodes to select a viewType (or any viewType)
• flip layout so that view nodes are on left and coordination type nodes are on right
• support meta-coordination
• support multi-level coordination
• make edge/node connection click areas bigger

Someday:

• option to render view within view node?
• convert coordination types to coordination objects using sub-flow https://reactflow.dev/examples/layout/sub-flows
• allow user of editor component to provide value-editor components corresponding to each coordination type?
  • fallback to text editor that performs JSON.stringify and JSON.parse
• implement a sidebar for drag-and-drop of type, scope, and view nodes https://reactflow.dev/examples/interaction/drag-and-drop