feature(create-expo-app): add --example flag to initialize from example

[byCedric]

Why

Fixes ENG-7493

How

• Based on the code from create-react-native-app, but adopted to this repository

Warning
I ran into the "premature close" error when testing this: isaacs/node-tar#321. I upgraded tar@6.1.11 to tar@6.1.13 to avoid this.

Test Plan

See tests and help info:

$ yarn create expo-app --help

# Show list of examples to create from
$ yarn create expo-app --example
# Or create a new example by name
$ yarn create expo-app --example with-router

[linear]

ENG-7493 Add support for expo/examples to create-expo-app

We currently only support the legacy templates because they're versioned but this causes us to need create-react-native-app for things like expo-router. We should add -e | --example to create-expo-app. This would differ from templates which are correctly versioned and accept sdk versions.

Alternatively we could add versioning to expo examples by cutting release branches but that seems like a fair amount of work for now.