These Postgres configuration variables are part of the `database.yaml` file
and don't need to be here.

This allows people to augment the Synapse image with custom tools and
addons without having to rebuild it from scratch.

If customizations are enabled, the playbook will build a new
`localhost/matrixdotorg/synapse:VERSION-customized` image
on top of the default one (`FROM matrixdotorg/synapse:VERSION`)
and with custom Dockerfile build steps.

For servers that self-build the Synapse image, the Synapse image will be
built first, before proceding to extend it the same way.

In the future, we'll also have easy to enable Dockerfile build steps
for modules that the playbook supports.

In the future, we'll also inject media storage providers that we support
into the `matrix_synapse_media_storage_providers_auto` list.

Fixes a regression introduced in d1b5681ba0.

Looks like `.finished` is a property on the main object, not on some
`.async_result` object.

We were previously trying to reach into `.rc`,
but there's no such thing if `async_result.finished == 0`.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2153

This mostly fixes `key-order` warnings around
`block` statements.

If someone is using Dendrite and enabling Grafana, we'll no longer
download Synapse dashboards.

If someone is not using node-exporter, we'll no longer download node
exporter dashboards.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2133

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2105

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2103

This keeps the configuration cleaner and hopefully prevents odd issues
if Synapse (by any chance) happens to interpret `pusher_instances: []`
as "no pushers", instead of as "push from the master process".

I haven't confirmed what an empty pushers/federation-senders list means,
so it's safer to just avoid it.

.. although.. manual configuration is discouraged in most cases.

As stream writer workers are also powered by the `generic_worker`
Synapse app, this necessitated that we provide means for distinguishing
between them and regular `generic_workers`.

I've also taken the time to optimize nginx configuration generation
(more Jinja2 macro usage, less duplication).

Worker names have also changed.
Workers are now named sequentially like this:
- `matrix-synapse-worker-0-generic`
- `matrix-synapse-worker-1-stream-writer-typing`
- `matrix-synapse-worker-2-pusher`

instead of `matrix-synapse-worker_generic_worker-18111` (indexed with a
port number).

People who modify `matrix_synapse_workers_enabled_list` directly will
need to adjust their configuration.

We do the same everywhere else. This is an omission.

`frontend_proxy` workers have been superseded by `generic_worker` workers.
Related to https://github.com/matrix-org/synapse/pull/13645

This is done in anticipation of this option's removal in the
upcoming Synapse v1.66.0 release (likely tomorrow).

See: https://matrix-org.github.io/synapse/v1.66/upgrade.html#delegation-of-email-validation-no-longer-supported

Regression since the mass-replace in 34cdaade0.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2054

* appservice: add and use matrix_homeserver_* vars

* appservice: use the new vars

* Apply suggestions from code review

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

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

Synapse no longer describes the stats as anonymized since the `server_name` is included.
https://github.com/matrix-org/synapse/pull/13321

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#var-spacing

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1939