This commit improves error messages for unstable APIs:
- `--unstable-broadcast-channel`
- `--unstable-cron`
- `--unstable-http`
- `--unstable-kv`
- `--unstable-temporal`
By providing information and hints what went wrong and how the
error can be fixed. It reuses the same infra that was added in
https://github.com/denoland/deno/pull/21764.