Add matrix-appservice-kakaotalk support

Adds support for: https://src.miscworks.net/fair/matrix-appservice-kakaotalk

This is pretty similar to
https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1977
which just appeared, but has mostly been done independently.

I've taken some inspiration and did some fixups based on that PR.
Thanks to https://github.com/hnarjis for taking the time to contribute!

Notable differences between this branch compared to that PR:

- better naming and documentation around the "configuration" variables
- no unnecessary (5 sec.) intentional delay when starting `matrix-appservice-kakaotalk-node.service`
- stores configuration in `config/`, not in `data/`
- passes configuration as read-only and starts the bridge with (`--no-update`) to ensure no changes are made to it
- starts containers more securely - with `matrix:matrix` user:group (not `root`) and
  reduced capabilities (`--cap-drop=ALL`)
- uses `tcp` for communication between the "node" and the appservice (simpler than sharing unix sockets)
- `registration.yaml` which is closer to the one generated by `matrix-appservice-kakaotalk` (no `de.sorunome.msc2409.push_ephemeral` stuff, etc.)
- `registration.yaml` which is more customizable (customizable bot username and prefix for puppets - see `matrix_appservice_kakaotalk_appservice_bot_username` and `matrix_appservice_kakaotalk_user_prefix`)
- less fragile and more extensible bridge permissions configuration via `matrix_appservice_kakaotalk_bridge_permissions`. Doing `{% if matrix_admin %}` in the bridge configuration sometimes causes syntax problems (I hit some myself) and is not ideal. Other bridges should be redone as well.
- configurable command prefix for the bridge, instead of hardcoding `!kt` (see `matrix_appservice_kakaotalk_command_prefix`)
- logging that is more consistent with the rest of the playbook (console / journald only, no logging to files), as well as configurable log level (via `matrix_appservice_kakaotalk_logging_level`)
- somewhat more detailed documentation (`docs/configuring-playbook-bridge-appservice-kakaotalk.md`)
- removed some dead code (data relocation tasks from `tasks/setup_install.yml`, as well as likely unnecessary SQLite -> Postgres migration)

roles/matrix-bridge-appservice-kakaotalk/templates/systemd/matrix-appservice-kakaotalk-node.service.j2

@@ -0,0 +1,38 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=appservice-kakaotalk-node bridge helper
+{% for service in matrix_appservice_kakaotalk_node_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_appservice_kakaotalk_node_systemd_wanted_services_list %}
+Wants={{ service }}
+{% endfor %}
+DefaultDependencies=no
+
+[Service]
+Type=simple
+Environment="HOME={{ matrix_systemd_unit_home_path }}"
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-appservice-kakaotalk-node 2>/dev/null || true'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-appservice-kakaotalk-node 2>/dev/null || true'
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-appservice-kakaotalk-node \
+			--log-driver=none \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--cap-drop=ALL \
+			--network={{ matrix_docker_network }} \
+			--mount type=bind,src={{ matrix_appservice_kakaotalk_config_path }}/node-config.json,dst=/config.json,ro \
+			{% for arg in matrix_appservice_kakaotalk_node_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			{{ matrix_appservice_kakaotalk_node_docker_image }} \
+			node src/main.js --config /config.json
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-appservice-kakaotalk-node 2>/dev/null || true'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-appservice-kakaotalk-node 2>/dev/null || true'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-appservice-kakaotalk-node
+
+[Install]
+WantedBy=multi-user.target

roles/matrix-bridge-appservice-kakaotalk/templates/systemd/matrix-appservice-kakaotalk.service.j2

@@ -0,0 +1,42 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=appservice-kakaotalk bridge
+{% for service in matrix_appservice_kakaotalk_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_appservice_kakaotalk_systemd_wanted_services_list %}
+Wants={{ service }}
+{% endfor %}
+DefaultDependencies=no
+
+[Service]
+Type=simple
+Environment="HOME={{ matrix_systemd_unit_home_path }}"
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-appservice-kakaotalk 2>/dev/null || true'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-appservice-kakaotalk 2>/dev/null || true'
+
+# Intentional delay, so that the homeserver (we likely depend on) can manage to start.
+ExecStartPre={{ matrix_host_command_sleep }} 5
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-appservice-kakaotalk \
+			--log-driver=none \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--cap-drop=ALL \
+			--network={{ matrix_docker_network }} \
+			--mount type=bind,src={{ matrix_appservice_kakaotalk_config_path }},dst=/config,ro \
+			--mount type=bind,src={{ matrix_appservice_kakaotalk_data_path }},dst=/data \
+			{% for arg in matrix_appservice_kakaotalk_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			{{ matrix_appservice_kakaotalk_docker_image }} \
+			python3 -m matrix_appservice_kakaotalk -c /config/config.yaml --no-update
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-appservice-kakaotalk 2>/dev/null || true'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-appservice-kakaotalk 2>/dev/null || true'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-appservice-kakaotalk
+
+[Install]
+WantedBy=multi-user.target