[Improvement] Bump Prerequisites to Node.js >= 16.0.0 and npm >= 7.0.0

[theoludwig]

Type of Improvement

Prerequisites

Proposal

Once, Node.js v16 in LTS, we should use as Prerequisites in README.md :

- [Node.js](https://nodejs.org/) >= 16.0.0
- [npm](https://npmjs.com/) >= 7.0.0

Things to do, once updated :

• Usage of npm@7, remove package-lock.json and install it again with npm install
• Uninstall uuid npm package and instead use built-in Node.js crypto.randomUUID, it is also faster! 🚀
• Refactor services/LeonInstance, usage of await this.runNpmScript (see: #34 (comment))
• Refactor imports of builtin modules with node: syntax (see: https://nodejs.org/api/esm.html#esm_node_imports)

NOTE: This is a BREAKING CHANGE.