feat: add vmcluster module (#363)

- manage vmstorage package, service and environment file
- manage vmselect package, service and environment file
- manage vminsert package, service and environment file
- manage vmagent package, service and environment file
- manage options for vmstorage, vmselect, vminsert, vmagent role

Reviewed-on: #363

modules/vmcluster/templates/vmagent.service.erb

@@ -0,0 +1,18 @@
+[Unit]
+Description=VictoriaMetrics vmagent service
+After=network.target
+
+[Service]
+Type=simple
+User=<%= @user %>
+Group=<%= @group %>
+Restart=always
+EnvironmentFile=<%= @vars_file %>
+ExecStart=<%= @exec_path %> -remoteWrite.tmpDataPath=<%= @data_path %> $OPTIONS
+
+PrivateTmp=yes
+NoNewPrivileges=yes
+ProtectSystem=full
+
+[Install]
+WantedBy=multi-user.target