Add validation for feature selection

[aalej]

Description

FIxes #5232

With the validation, the scenario if (!setup.features || setup.features?.length === 0) is very unlikely to happen, but just in case it does, it might be a good idea to keep

firebase-tools/src/commands/init.ts

Lines 207 to 214 in 9b4d5bc

	if (!setup.features || setup.features?.length === 0) {
	throw new FirebaseError(
	"Must select at least one feature. Use " +
	clc.bold(clc.underline("SPACEBAR")) +
	" to select features, or specify a feature by running " +
	clc.bold("firebase init [feature_name]"),
	);
	}

Scenarios Tested

Run firebase init then press enter without selecting any features

$ firebase init

     ######## #### ########  ######## ########     ###     ######  ########
     ##        ##  ##     ## ##       ##     ##  ##   ##  ##       ##
     ######    ##  ########  ######   ########  #########  ######  ######
     ##        ##  ##    ##  ##       ##     ## ##     ##       ## ##
     ##       #### ##     ## ######## ########  ##     ##  ######  ########

You're about to initialize a Firebase project in this directory:

  /Users/PATH/Desktop/firebase-tools/issues/5232

Before we get started, keep in mind:

  * You are initializing within an existing Firebase project directory

? Which Firebase features do you want to set up for this directory? Press Space to select features, then Enter to confirm your choices. (Press <space> to select, <a> to toggle
 all, <i> to invert selection, and <enter> to proceed)
❯◯ Data Connect: Set up a Firebase Data Connect service
 ◯ Firestore: Configure security rules and indexes files for Firestore
 ◯ Genkit: Setup a new Genkit project with Firebase
 ◯ Functions: Configure a Cloud Functions directory and its files
 ◯ App Hosting: Enable web app deployments with App Hosting
 ◯ Hosting: Configure files for Firebase Hosting and (optionally) set up GitHub Action deploys
 ◯ Storage: Configure a security rules file for Cloud Storage
> Must select at least one feature. Use SPACEBAR to select features, or specify a feature by running firebase init [feature_name]

Sample Commands