Two small changes:
- In our BYONM errors, suggest running `deno install` instead of `npm
install` if `DENO_FUTURE` is set
- Only emit warning about `deno install` changes if you do `deno install
<foo>` with deno_future unset
Fixes a regression introduced in
https://github.com/denoland/deno/pull/24170, where we wouldn't actually
set up the node modules dir on `deno install` if there was an up to date
deno lockfile present.
Previously we were relying on the fact that resolving pending module
resolution called `cache_packages` (which sets up the node modules dir).
When pending resolutions were removed, and the `resolve_pending`
function with it, we also removed the `cache_packages` call needed to
set up node modules.
