Save "Backup Configuration" .json file inside backup folder

[p44]

Can be interesting to save "Backup Configuration" json file also inside backup folder.

This because in some situation, eg. in case of main Cloudron instance not accessible, can be hard to retrieve file .json file.

[girish]

I think the reason it's not done is simply because for .tgz format, the config file will end up inside the backup. The user then has to know to download the full backup and then extract this file out.

[girish]

Also see https://forum.cloudron.io/topic/4306/provide-ui-support-for-choosing-app-package-version-during-installation