Detect URL: Add support for request forwarding by HTTP_X_FORWARDED_PR…

…OTO header (Kubernetes support).

Detect URL: Add support for request forwarding by HTTP_X_FORWARDED_PR…

…OTO header (Kubernetes support).

README: Add relative URL info.

Url::getRelativeUrl(): Add argument for strip query parameters.

Url: Add field with relative URL.

README: Add how to use.

Add support for PHP 8

Readme: Add simple info

Fix Coding standard by current Nette rules

URL: Safe BasePath detection by UrlScript.