Let's extend the lifecycle to make it easier to wrap v3 buildpacks so they can be used on v2a/v2b platforms.

[ssisil]

Add the following lifecycle inputs:

1. -launch, $PACK_LAUNCH_DIR, default in stack images: /workspace
2. -cache, $PACK_CACHE_DIR, default in stack images: /cache
3. -app, $PACK_APP_DIR, default in stack images: /workspace/app

Notes

• logic on launcher.go:29 should whitelist buildpack IDs, or something like that