docker: use mysql and postgres from latest fake-data-gen

docker/blocks/mysql/docker-compose.yaml

@@ -12,3 +12,10 @@
       - /etc/timezone:/etc/timezone:ro
     command: [mysqld, --character-set-server=utf8mb4, --collation-server=utf8mb4_unicode_ci, --innodb_monitor_enable=all]
 
+  fake-mysql-data:
+    image: grafana/fake-data-gen
+    network_mode: bridge
+    environment:
+      FD_DATASOURCE: mysql
+      FD_PORT: 3306
+

docker/blocks/postgres/docker-compose.yaml

@@ -7,3 +7,10 @@
     ports:
       - "5432:5432"
     command: postgres -c log_connections=on -c logging_collector=on -c log_destination=stderr -c log_directory=/var/log/postgresql
+
+  fake-postgres-data:
+    image: grafana/fake-data-gen
+    network_mode: bridge
+    environment:
+      FD_DATASOURCE: postgres
+      FD_PORT: 5432