Notify the developer of unmaintained Vaadin versions

The API introduced with #51 allows us to notify the developer if they're using an unmaintained Vaadin version. We should do this by:

checking the current vaadin-server version from the SBOM
verify if it's either in AppSecService:: getSupportedFramework7Versions or AppSecService:: getSupportedFramework8Versions
if not, notify the developer via
- push notification
- warning message in place of the Vaadin analysis fields in the vulnerability details (i.e. they won't be getting any for that version)

vaadin / appsec-kit