Bugfixes:

- Calling static trait method PushNotification\Message\Config\Provider::apple is deprecated, it should only be called on a class using the trait
- Calling static trait method PushNotification\Message\Config\Provider::google is deprecated, it should only be called on a class using the trait

Bugfix getenv

- Bugfix PSR-0 Autoloading

- Update Guzzle dependency up to 7.x
- PHP min. requirement version 8.1

Bugfix.

Implementation of loc-key and loc-args properties for IOSMessages

fixed classnames and namespaces of AppleMessageInterface and GoogleMe…

…ssageInterface

fixed namespace for MessageConfig

fixed namespace for MessageFactory

fixed filename and namespace of InvalidArgumentException

fixed naming of service-folder identical to namespace