This integrates a feature that was previously reserved for enterprise
users, according to https://github.com/caddyserver/caddy/issues/2786.
The /config and /id endpoints make granular config changes possible as
well as the exporting of the current configuration.
The /load endpoint has been modified to wrap the /config handler so that
the currently-running config can always be available for export. The
difference is that /load allows configs of varying formats and converts
them using config adapters. The adapted config is then processed with
/config as JSON. The /config and /id endpoints accept only JSON.
Along with several other changes, such as renaming caddyhttp.ServerRoute
to caddyhttp.Route, exporting some types that were not exported before,
and tweaking the caddytls TLS values to be more consistent.
Notably, we also now disable automatic cert management for names which
already have a cert (manually) loaded into the cache. These names no
longer need to be specified in the "skip_certificates" field of the
automatic HTTPS config, because they will be skipped automatically.