Previously, it had to go through matrix-nginx-proxy.
It's exposed to Traefik directly via container labels now.

It's probably unnecessary, as this user is only used in the borg container
internally, but.. It doesn't hurt to set it to `matrix`.

* fix: only add element related entries to client well-known if element is enabled

* Fix matrix-base/defaults/main.yml syntax

---------

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

The playbook tries to avoid such variables which are sometimes defined
and sometimes not. We'd rather not check for `is defined`.

None of the other roles use handlers.

We rely on com.devture.ansible.role.systemd_service_manager to reload services when it's necessary to do so.

Leaving an orphan directory is okay and can be improved later on.

* fix uploads from incoming emails into matrix threads
* fix emails dequeue (account data cleanup)
* rewrite recipients handling (Cc, To, etc.)

Current draupnir does not listen to its name. This config change fixes this bug. This bodge is able to be removed once this is fixed upstream.

main.yml is not included due to that its changed separately.

Related to 6a31fba346d9da434, 6a31fba346.

Related to https://github.com/Awesome-Technologies/synapse-admin/issues/322

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2444

Check for empty string instead of Null to verify if an openid_server_name is pinned.

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

This gets us started on adding a Traefik role and hooking Traefik:

- directly to services which support Traefik - we only have a few of
  these right now, but the list will grow

- to matrix-nginx-proxy for most services that integrate with
  matrix-nginx-proxy right now

Traefik usage should be disabled by default for now and nothing should
change for people just yet.

Enabling these experiments requires additional configuration like this:

```yaml
devture_traefik_ssl_email_address: '.....'

matrix_playbook_traefik_role_enabled: true
matrix_playbook_traefik_labels_enabled: true

matrix_ssl_retrieval_method: none

matrix_nginx_proxy_https_enabled: false

matrix_nginx_proxy_container_http_host_bind_port: ''
matrix_nginx_proxy_container_federation_host_bind_port: ''

matrix_nginx_proxy_trust_forwarded_proto: true

matrix_nginx_proxy_x_forwarded_for: '$proxy_add_x_forwarded_for'

matrix_coturn_enabled: false
```

What currently works is:
reverse-proxying for all nginx-proxy based services **except** for the Matrix homeserver
(both Client-Server an Federation traffic for the homeserver don't work yet)