Add initial role for Dendrite as alternative Matrix server

roles/matrix-dendrite/tasks/dendrite/setup_uninstall.yml

@@ -0,0 +1,28 @@
+- name: Check existence of matrix-dendrite service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-dendrite.service"
+  register: matrix_dendrite_service_stat
+
+- name: Ensure matrix-dendrite is stopped
+  service:
+    name: matrix-dendrite
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_dendrite_service_stat.stat.exists"
+
+- name: Ensure matrix-dendrite.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-dendrite.service"
+    state: absent
+  when: "matrix_dendrite_service_stat.stat.exists"
+
+- name: Ensure systemd reloaded after matrix-dendrite.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_dendrite_service_stat.stat.exists"
+
+- name: Ensure Dendrite Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_dendrite_docker_image }}"
+    state: absent