Move roles/matrix* to roles/custom/matrix*

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.

roles/custom/matrix-synapse/tasks/ext/rest-auth/setup.yml

@@ -0,0 +1,7 @@
+---
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/ext/rest-auth/setup_install.yml"
+  when: matrix_synapse_ext_password_provider_rest_auth_enabled | bool
+
+- ansible.builtin.import_tasks: "{{ role_path }}/tasks/ext/rest-auth/setup_uninstall.yml"
+  when: "not matrix_synapse_ext_password_provider_rest_auth_enabled | bool"

roles/custom/matrix-synapse/tasks/ext/rest-auth/setup_install.yml

@@ -0,0 +1,36 @@
+---
+
+- name: Fail if REST Auth endpoint not configured
+  ansible.builtin.fail:
+    msg: "You have enabled the REST Auth password provider, but have not configured its endpoint in the `matrix_synapse_ext_password_provider_rest_auth_endpoint` variable. Consult the documentation."
+  when: "matrix_synapse_ext_password_provider_rest_auth_endpoint == ''"
+
+- name: Download matrix-synapse-rest-auth
+  ansible.builtin.get_url:
+    url: "{{ matrix_synapse_ext_password_provider_rest_auth_download_url }}"
+    dest: "{{ matrix_synapse_ext_path }}/rest_auth_provider.py"
+    force: true
+    mode: 0440
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  register: result
+  retries: "{{ matrix_geturl_retries_count }}"
+  delay: "{{ matrix_geturl_retries_delay }}"
+  until: result is not failed
+
+- ansible.builtin.set_fact:
+    matrix_synapse_password_providers_enabled: true
+
+    matrix_synapse_container_extra_arguments: >
+      {{
+        matrix_synapse_container_extra_arguments | default([])
+        +
+        ["--mount type=bind,src={{ matrix_synapse_ext_path }}/rest_auth_provider.py,dst={{ matrix_synapse_in_container_python_packages_path }}/rest_auth_provider.py,ro"]
+      }}
+
+    matrix_synapse_additional_loggers: >
+      {{
+        matrix_synapse_additional_loggers
+        +
+        [{'name': 'rest_auth_provider', 'level': 'INFO'}]
+      }}

roles/custom/matrix-synapse/tasks/ext/rest-auth/setup_uninstall.yml

@@ -0,0 +1,6 @@
+---
+
+- name: Ensure matrix-synapse-rest-auth doesn't exist
+  ansible.builtin.file:
+    path: "{{ matrix_synapse_ext_path }}/rest_auth_provider.py"
+    state: absent