Replace recognized service URLs with privacy friendly alternatives

[walterl]

Like privacy-redirect: Automatically replace URLs to recognized services, with one to a privacy friendly alternative.

Make it very clear and easy to revert back to the original URL.

The user must be able to configure this functionality in the following ways:

• Enable/disable it completely
• If enabled, replace URL with privacy friendly service automatically or manually.
• Manage replacement URLs for services independently. Perhaps a solution similar to ClearURLs's rules JSON used by uroute.url.clean_url().