Allow nodes to register completions for the Typed Input widget

[danvirsen]

Let's say I have a custom node that adds a couple of properties to "msg".
It would be really nice if there was a way to add these properties to the list of completions for the Typed Input widget.

Currently the autocomplete list is hardcoded in the widget (packages/node_modules/@node-red/editor-client/src/js/ui/common/typedInput.js:106).

A really smooth experience for node developers would be if RED.nodes.registerType allowed a list of completions to be set.

Is this a feature that would make sense to people?
If yes, how could this be implemented in a good way?
Also, I'm focusing strictly on the Typed Input widget here. It might make sense to zoom out a bit and look at more widgets.