feature: add monorepo tooling to minimize maintenance

[byCedric]

Why

This is another attempt to implement proper monorepo tooling to minimize maintenance as much as possible.

How

• Added turbo as monorepo tool
• Configured through turbo.json (with .vscode/settings.json to set it to jsonc/json5)
• Revamped snackager/Dockerfile to remove hardcoded paths
  • This now uses turbo to remove unused workspaces, which auto-updates once they are added/removed.
  • It also reuses previously built files when possible, minimizing build time as well.
• Revamped website/Dockerfile to remove hardcoded paths (same as snackager)

Docker sizes

Dockerfile	Before	After
snackager
snackpub
website

Test Plan

Since this is a big change, have to fully test this on staging first.

[Kudo]

basically looks good to me. good to learn the turbo prune --docker.
didn't see any big problem in this pr, just have to deploy and we will know.

[byCedric]

@Kudo We definitely need to just try it in deployment, that's why Snack staging is already running this image 😄 And so far, its looking good.

Edit: both Website and Snackager are now running these Dockerfiles 👍 It's also insane to me how much build cache we still shipped with the website image. It's now reduced by a factor of 3.9x 🙈