Added property pane navigation sample

[GuidoZam]

• [x] New sample
• [ ] Bug fix/update
• [ ] Related issues: fixes #X, partially #Y, mentioned in #Z

What's in this Pull Request?

Added a new sample that illustrate how to use the navigation between pages in the property pane of a web part.

Node Version

Node version used: 16.20.2

Checklist

• [x] My pull request affects only ONE sample.
• [x] My sample builds without any warnings
• [x] I have updated the README.md file's Version history. For new samples, created a new README.md file matching this template
• [x] My README.md has at least one static high-resolution screenshot (i.e. not a GIF) located in the assets folder.
• [x] My README.md contains complete setup instructions, including pre-requisites and permissions required
• [x] My solution includes a .nvmrc file indicating the version of Node.js

[github-actions[bot]]

Validation failed!

File: samples/react-property-pane-navigation/assets/sample.json

• Invalid 'url' property: The provided URL is not responding correctly!
• Invalid url for thumbnail #1 property: The provided URL is not responding correctly!
• Invalid url for thumbnail #2 property: The provided URL is not responding correctly!
• Invalid url for thumbnail #3 property: The provided URL is not responding correctly!
• Invalid url for thumbnail #4 property: The provided URL is not responding correctly!