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-base/tasks/server_base/setup.yml

@@ -0,0 +1,47 @@
+---
+
+- ansible.builtin.include_tasks: "{{ role_path }}/tasks/server_base/setup_redhat.yml"
+  when: ansible_os_family == 'RedHat' and ansible_distribution_major_version | int < 8
+
+- ansible.builtin.include_tasks: "{{ role_path }}/tasks/server_base/setup_redhat8.yml"
+  when: ansible_os_family == 'RedHat' and ansible_distribution_major_version | int > 7 and ansible_distribution_major_version | int < 30
+
+- ansible.builtin.include_tasks: "{{ role_path }}/tasks/server_base/setup_fedora.yml"
+  when: ansible_os_family == 'RedHat' and ansible_distribution_major_version | int > 30
+
+- when: ansible_os_family == 'Debian'
+  block:
+  # ansible_lsb is only available if lsb-release is installed.
+  - name: Ensure lsb-release installed
+    ansible.builtin.apt:
+      name:
+        - lsb-release
+      state: present
+      update_cache: true
+    register: lsb_release_installation_result
+
+  - name: Reread ansible_lsb facts if lsb-release got installed
+    ansible.builtin.setup:
+      filter: ansible_lsb*
+    when: lsb_release_installation_result.changed
+
+  - ansible.builtin.include_tasks: "{{ role_path }}/tasks/server_base/setup_debian.yml"
+    when: (ansible_os_family == 'Debian') and (ansible_lsb.id != 'Raspbian')
+
+  - ansible.builtin.include_tasks: "{{ role_path }}/tasks/server_base/setup_raspbian.yml"
+    when: (ansible_os_family == 'Debian') and (ansible_lsb.id == 'Raspbian')
+
+- ansible.builtin.include_tasks: "{{ role_path }}/tasks/server_base/setup_archlinux.yml"
+  when: ansible_distribution == 'Archlinux'
+
+- name: Ensure Docker is started and autoruns
+  ansible.builtin.service:
+    name: docker
+    state: started
+    enabled: true
+
+- name: "Ensure ntpd is started and autoruns"
+  ansible.builtin.service:
+    name: "{{ matrix_ntpd_service }}"
+    state: started
+    enabled: true