Add support for os-families-exclude in extensions composer.json

[alexandre-daubois]

Fix #106

Allows to specify OS families which the extension is incompatible with:

{
    "name": "myvendor/myext",
    "php-ext": {
        "extension-name": "myext",
        "configure-options": [
            // ...
        ],
        "os-families-exclude": ['windows', 'darwin']
    }
}

When the syntax is validated, I'll create a PR in Composer to allow the new key in the Package::$phpExt property.

Related to ThePHPF/pie-design#29

[alexandre-daubois]

Revamped the whole PR to address your comments.

• Things are done in ResolveDependencyWithComposer instead of CommandHelper
• An enum holding OS families is added
• It is added to the TargetPlatform
• PhpBinaryPath is used to determine the OS family, just like the OS

[tillkruss]

This is great, love to exclude windows.

[alexandre-daubois]

Remaining CS warnings should be fixed once composer/composer#12218 is merged

[asgrim]

PR composer/composer#12218 is now merged; please can you update the composer req, that should fix the static analysis

[alexandre-daubois]

Here you go, all green! 🙂

[asgrim]

Thanks @alexandre-daubois

[Seldaek]

It's now tagged as part of composer 2.8.4

[asgrim]

Thanks @Seldaek !