Draft: Add role for Caddy web server

Our current nginx+acmebot setup is broken in Debian stable. I am not happy with the webserver role in various points anyway, and the ACME problem still stands. Caddy solves both.

Draft, because I still need to write docs.

added 3 commits

• ce6052f9 - caddy: Set loop labels for better overview
• 54b41c83 - caddy: Fix disable inactive site/config logic
• 2f213d48 - caddy: Separate site config templating task in its own file

Compare with previous version

added 10 commits

• 2f213d48...50eab233 - 6 commits from branch master
• 38c6dd58 - Add role for Caddy web server
• 34eeedb5 - caddy: Set loop labels for better overview
• a584e9ae - caddy: Fix disable inactive site/config logic
• 89d3b7ac - caddy: Separate site config templating task in its own file

Compare with previous version