Deprecated dependencies in client

[tgranqvist]

When cloning this template and running npm install, I get the following warnings:

npm warn deprecated inflight@1.0.6: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.
npm warn deprecated glob@7.2.3: Glob versions prior to v9 are no longer supported
npm warn deprecated node-domexception@1.0.0: Use your platform's native DOMException instead

I opted to use ES6 modules in the frontend, haven't checked how it behaves if not using this alternative.