Allow Trace to accept a Future as its data source

[liamgriffiths]

Warning

The supported server code for this is finished, but not yet released.

Enables "Trace" Futures (produces through property access) to reference other Futures that produce values in addition to Nodes.

For example,

  const f = sb.jq<"object">({ foo: { bar: "baz" } }, ".", "object");

  const a = new Box({
    value: {
      x: f,
      y: f.get("foo.bar"),
    },
  });