containers definition - allow to define caddy_routes

[szaimen]

Address part of https://github.com/nextcloud/all-in-one/discussions/1581

todo

• [ ] merge it with containersfetcher
• [ ] retreive it on container start
• [ ] merge it as env
• [ ] geneerate the files as imports during startup of apache
• [ ] store them in tmpfs volume instead of in volume? (if so, remove some of the logic again from startup...
• [ ] remove it from update-yaml.sh
• [ ] maybe also use it for default apps? improves testing