Provide build agent for Node.js 18

[cschweikert]

The new LTS version of Node.js - version 18 - is available now. See also https://nodejs.org/en/about/releases/

The Node.js-specific Jenkins build agents are published per Node.js version. The latest is currently for Node.js version 16 (https://github.com/opendevstack/ods-quickstarters/tree/master/common/jenkins-agents/nodejs16).

For providing a new agent for version 18 I guess the following steps should be fine:

• providing a new agent in the ./common/jenkins-agents folder similar to the one for Node.js 16
• update build scripts
• update documentation

A very similar update happened recently for the Node.js 16 agent: https://github.com/opendevstack/ods-quickstarters/pull/764