Matrix Authentication Support for Jitsi

This extends the collection with support for seamless authentication at the Jitsi server using Matrix OpenID.

1. New role for installing the [Matrix User Verification Service](https://github.com/matrix-org/matrix-user-verification-service)
2. Changes to Jitsi role: Installing Jitsi Prosody Mods and configuring Jitsi Auth
3. Changes to Jitsi and nginx-proxy roles: Serving .well-known/element/jitsi from jitsi.DOMAIN
4. We updated the Jitsi documentation on authentication and added documentation for the user verification service.

roles/custom/matrix-user-verification-service/tasks/setup_uninstall.yml

@@ -0,0 +1,35 @@
+---
+
+- name: Check existence of matrix-user-verification-service service
+  stat:
+    path: "{{ matrix_systemd_path }}/{{ matrix_user_verification_service_systemd_service_name }}"
+  register: matrix_user_verification_service_service_stat
+
+- name: Ensure matrix-user-verification-service is stopped
+  service:
+    name: "{{ matrix_user_verification_service_systemd_service_basename }}"
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_user_verification_service_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-user-verification-service.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/{{ matrix_user_verification_service_systemd_service_name }}"
+    state: absent
+  when: "matrix_user_verification_service_service_stat.stat.exists|bool"
+
+- name: Ensure systemd reloaded after matrix-user-verification-service.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_user_verification_service_service_stat.stat.exists|bool"
+
+- name: Ensure Matrix user-verification-service paths don't exist
+  file:
+    path: "{{ matrix_user_verification_service_base_path }}"
+    state: absent
+
+- name: Ensure user-verification-service Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_user_verification_service_docker_image }}"
+    state: absent