Chase down warning about `util._extend`

[kklamberty]

Newer versions of Node have started to complain about the use of util._extend, which was apparently never meant to be used outside of Node (or something). I'm not sure which of our dependencies might be using this or if we are using it in a way that I just can't find using search. It seems to somehow relate to using the side nav.

(node:94688) [DEP0060] DeprecationWarning: The `util._extend` API is deprecated. Please use Object.assign() instead.
(Use `node --trace-deprecation ...` to show where the warning was created)

[kklamberty]

I think I'm able to fix this error by just swapping out extend for Object.assign in client/node_modules/http-proxy/lib/http-proxy/common.js and client/node_modules/http-proxy/lib/http-proxy/index.js, but I'm not totally sure what that means for how to fix it. From http-party/node-http-proxy#1666 it looks like it has been merged into http-proxy, but maybe not released yet.

[kklamberty]

https://github.com/terraware/terraware-web/pull/3875/files

(Consider adding something like this to the package.json file.)

,
  "overrides": {
    "http-proxy-middleware": {
      "http-proxy": "github:nikeee/node-http-proxy#b42c38fc3486ee8ad4374cc2397458b6e4cd99ca"
    }
  }