Prompt for PHP version during magebox init

[Aquive]

Adds an interactive PHP version prompt to magebox init, defaulting to the value from global config (default_php). Supported versions are shown as hints.

[peterjaap]

Can we also add reading the PHP version from composer.json?

{
    "config": {
        "platform": {
            "php": "8.3"
        }
    }
}

and/or

{
    "require": {
        "php": "~8.3",
        ....
     }
}

[Aquive]

Yeah had the same idea, see #96

I'll add that part later.