This commit introduces functionality to send POST requests with
an 'application/json' content type using a Selenium WebDriver.

The core logic involves:
1.  Serializing a Python dictionary to a JSON string.
2.  Escaping single quotes in the JSON string to allow safe embedding
    into a JavaScript single-quoted string literal.
3.  Dynamically generating an HTML5 document with embedded JavaScript.
4.  The JavaScript uses the `fetch` API to make the POST request with
    the correct 'Content-Type': 'application/json' header and the
    JSON payload.
5.  The HTML page (and thus the script) is loaded into the WebDriver
    using a data URI.
6.  Status messages (success/error) are displayed in a `div` on the
    generated page and also logged to the browser console.
7.  The function waits for the operation to complete and returns
    the status message from the page.

A demonstration example using `https://httpbin.org/post` is included
to showcase the functionality, including handling of successful requests,
network errors, and HTTP error responses.

This approach is designed for scenarios where direct Python HTTP requests
might be insufficient due to browser-specific behaviors or JavaScript
dependencies on target sites.