Consider enforcing development Node version using `engines` plugin

The `engines` plugin will, when `yarn` is run, check the Node version specified in the `engines` field `package.json` and/or the version specified in `.nvmrc` and throw if the user is not using that version. This could help resolve problems when contributors outside the Wallet Framework team are working with the `core` repo and not using the correct version (because they haven't run `nvm use`).

See: https://github.com/devoto13/yarn-plugin-engines

Start by reviewing the core repository's package.json engines field and .nvmrc, then read the linked yarn-plugin-engines documentation to understand its integration. Done means running yarn checks the declared Node version and rejects an unsupported version, helping contributors use the required development environment.

Written by the indexing model from the issue text.