Lookout: update Node and Yarn toolsets for development and building

[richscott]

The Lookout codebase currently uses/assumes that development and builds are done with Node version 16 (specifically, v16.14.2) and Yarn 1.x (specifically, 1.22.18). Node version 16 reached its End-of-Life status on Sept 11, 2023, and will not be receiving any more updates. See https://nodejs.dev/en/about/releases/ for the support calendar.

The Lookout codebase should be tested with at least Node version 18 (which is in LTS status through at least April 2025) or version 20 (which will be supported through April 2026). All container Dockerfiles & CI scripts should be updated as well. The version of Yarn should be updated to version 3.6.x (or higher) and thoroughly tested. Note that version 3 of Yarn has (optional) different handling of node_modules installation - see https://dev.to/arcanis/yarn-3-0-performances-esbuild-better-patches-e07 .