Since Composer can't recursively use repositories, we can't actually use a local package to deal with this. We're going to keep the local package to separate the dependencies but we need to add autoload keys in the root package's `composer.json`
In order to avoid problems posed by potentially including the unconverted dependencies in the root autoloader, this package will hold all dependencies that require conflict avoidance.
This also updates the woocommerce/woocommerce-admin and woocommerce/woocommerce-blocks packages as their dependence on `composer/installers` precludes update otherwise
A custom fork of the coenjacobs/mozart package is now used to change
the namespace of the appropriate packages (only league/container
for now) instead of the previously used prefix-vendor-namespaces script.
The packages are now moved to the src/Internal/Vendor namespace instead
of being modified in-place in the vendor directory. The namespaces
are thus now prefixed with Automattic\WooCommerce\Internal\Vendor
(previously it was just Automattic\WooCommerce\Vendor).