Move mautrix telegram and whatsapp into separate roles

The goal is to move each bridge into its own separate role.
This commit starts off the work on this with 2 bridges:
- mautrix-telegram
- mautrix-whatsapp

Each bridge's role (including these 2) is meant to:

- depend only on the matrix-base role

- integrate nicely with the matrix-synapse role (if available)

- integrate nicely with the matrix-nginx-proxy role (if available and if
required). mautrix-telegram bridge benefits from integrating with
it.

- not break if matrix-synapse or matrix-nginx-proxy are not used at all

This has been provoked by #174 (Github Issue).

roles/matrix-bridge-mautrix-whatsapp/defaults/main.yml

@@ -0,0 +1,21 @@
+# mautrix-whatsapp is a Matrix <-> Whatsapp bridge
+# See: https://github.com/tulir/mautrix-whatsapp
+
+matrix_mautrix_whatsapp_enabled: true
+
+matrix_mautrix_whatsapp_docker_image: "tulir/mautrix-whatsapp:latest"
+
+matrix_mautrix_whatsapp_base_path: "{{ matrix_base_data_path }}/mautrix-whatsapp"
+
+matrix_mautrix_whatsapp_homeserver_address: "https://{{ matrix_server_fqn_matrix }}"
+matrix_mautrix_whatsapp_homeserver_domain: "{{ matrix_domain }}"
+matrix_mautrix_whatsapp_appservice_address: "http://matrix-mautrix-whatsapp:8080"
+
+# A list of extra arguments to pass to the container
+matrix_mautrix_whatsapp_container_extra_arguments: []
+
+# List of systemd services that matrix-mautrix-whatsapp.service depends on.
+matrix_mautrix_whatsapp_systemd_required_services_list: ['docker.service']
+
+# List of systemd services that matrix-mautrix-whatsapp.service wants
+matrix_mautrix_whatsapp_systemd_wanted_services_list: []