Use overriden composer bin-dir if it exists

Problem/Motivation

A project might have a different bin-dir for its executables (phpcs/phpstan). Check if it exists in the project's composer and use this path for jobs
https://getcomposer.org/doc/06-config.md#bin-dir

Steps to reproduce

Add the following to the composer.json of a project

    "config": {
        "bin-dir": "bin",
    }

Get the following error
sudo: vendor/bin/phpunit: command not found

Proposed resolution

Change scripts/expand_composer_json.php to check for this?

Remaining tasks

User interface changes

API changes

Data model changes