Add the ability to pick a package manager of choice while scaffolding

[jamesgeorge007]

Is your feature request related to a problem? Please describe.
Currently, there isn't any way to specify a package manager of choice while generating the boilerplate (init | loader | plugin).

webpack-cli/packages/generators/src/init-generator.ts

Line 103 in 060268b

const packager = this.utils.getPackageManager();

webpack-cli/packages/webpack-cli/lib/utils/get-package-manager.js

Lines 15 to 31 in 060268b

	const hasLocalNpm = fs.existsSync(path.resolve(process.cwd(), "package-lock.json"));
	if (hasLocalNpm) {
	return "npm";
	}
	const hasLocalYarn = fs.existsSync(path.resolve(process.cwd(), "yarn.lock"));
	if (hasLocalYarn) {
	return "yarn";
	}
	const hasLocalPnpm = fs.existsSync(path.resolve(process.cwd(), "pnpm-lock.yaml"));
	if (hasLocalPnpm) {
	return "pnpm";
	}

With the current approach, npm is always chosen if creating a new project in an empty directory.

Describe the solution you'd like
It'd be nice to have a prompt that shows up with the available installers so that one can go ahead with the preferred package manager.

Describe alternatives you've considered
N/A

Additional context
N/A

[alexander-akait]

Yep, PR welcome