Adds the framework for a system to automate display of a curated list of
recommended widgets to the node.
As part of this, a return to display of "image previews" was made.
This code is causing lots of problems. Much of the logic is dependent
upon the actual node going through the draw loop. As nodes in the
subgraph don't receive redraws, there's lots of issues with managing the
initial display and ensuring that an initial draw occurs.
This commit includes support for updating previews, but is more brittle
than I would like.
While node.properties function with anything serializeable, the format
for proxyWidgets is not a valid option for type. After great
consideration, all access to and from this value goes through a JSON
serialization and parsing always includes a zod validation step.
This is sturdier to outside misuse, has even lower risk of custom node
breakage, and means that there's now proper type checking at the
boundries of interaction.
Performance was a major concern against this, but the path is quite
cold. I estimate the value of optimization here to be 3-4 orders of
magnitude less important than anything occuring during the draw loop
(like access to proxyWidget elements)
