Hotfix: important updates

For supported versions (see Product EOL), it is possible to apply important updates (hotfix) without necessarily updating vtenext to the latest version.

Updating versions often cannot be done immediately due to code customizations or staff training requirements.
We have therefore introduced a new tool that allows you to install stability and security improvements for installations that cannot be updated immediately.

These hotfixes include performance improvements, impactful bug fixes, security patches, etc., and it is therefore recommended to apply them immediately.

From 25.02.2 the notification and installation of hotfix is integrated into the update system in Settings. For previous supported versions they are available via the vteUpdater script.