`ionic info` without having run `npm install`

Running `ionic info` on a fresh checkout of a project without running `npm install` first leads to some output like this:

```
λ ionic info

[ERROR] Error loading ionic-angular package.json: Error: Cannot find module 'ionic-angular/package'
[ERROR] Error loading @ionic/app-scripts package.json: Error: Cannot find module '@ionic/app-scripts/package'

Ionic:

ionic (Ionic CLI) : 4.10.3 (C:\Users\Jan\scoop\persist\nvm\nodejs\v10.15.1\node_modules\ionic)
Ionic Framework : not installed
@ionic/app-scripts : not installed

Cordova:

cordova (Cordova CLI) : 9.0.0
Cordova Platforms : not available
Cordova Plugins : not available

System:

ios-deploy : 1.9.2
NodeJS : v10.15.1 (C:\Users\Jan\scoop\apps\nvm\current\nodejs\nodejs\node.exe)
npm : 6.4.1
OS : Windows 10
Xcode : Xcode 10.1
```

It might be useful to recognize that this is probably because of a missing `npm install` and educate the user about this.

Start by reproducing `ionic info` from a fresh checkout before running `npm install`, then trace the `ionic info` command's package-detection and error-reporting path. Done means the command explains that dependencies are missing and points the user toward installing them, without misleading package-loading errors.

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