Feature: fine-grained collapsed control

[rotsee]

Thank you for this project! Here is a feature request:

Allow collapsed to recieve a function that determines if a node should be open or not, given its depth and content.

Use case: Sometimes it is useful to hide not only nodes below a certain depth, but also those with very many children.

It would be nice to be able to do something like this: collapsed: (key, depth, content) => depth > 2 || content.length > 200

This would allow all sorts of custom behaviour:
collapsed: (key, depth, content) => key.startsWith("_")

For an example of this, see https://github.com/microlinkhq/react-json-view where shouldCollapse offers this functionality