title	issue
Add API Expectations	NEXT-13357

Core

Added new Subscriber \Shopware\Core\Framework\Api\EventListener\ExpectationSubscriber

API

Added new header sw-expect-packages for admin-api
- This header can be used to specify as requester that some packages with specific version are available on server side
- Examples:
  - shopware/core:~6.4 -> Expects on server side running at least Shopware 6.4, otherwise the request will fail with an 417
  - shopware/core:~6.4,swag/paypal:* => Expects on server side running at least Shopware 6.4 and PayPal is installed, otherwise the request will fail with an 417
- The delimiter for multiple packages is ,. Separator for package name and constraint is :.