The newly extracted role also has native Traefik support,
so we no longer need to rely on `matrix-nginx-proxy` for
reverse-proxying to Ntfy.
The new role uses port `80` inside the container (not `8080`, like
before), because that's the default assumption of the officially
published container image. Using a custom port (like `8080`), means the
default healthcheck command (which hardcodes port `80`) doesn't work.
Instead of fiddling to override the healthcheck command, we've decided
to stick to the default port instead. This only affects the
inside-the-container port, not any external ports.
The new role also supports adding the network ranges of the container's
multiple additional networks as "exempt hosts". Previously, only one
network's address range was added to "exempt hosts".
This role is usable on its own and it's not tied to Matrix, so
extracting it out into an independent role that we install via
ansible-galaxy makes sense.
This also fixes the confusion from the other day, where
`matrix_postgres_*` had to be renamed to `devture_postgres_*`
(unless it was about `matrix_postgres_backup_*`).
We now can safely say that ALL `matrix_postgres_*` variables need to be
renamed.
Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2305
