Dynamic pages: add class to body for each dynamic path part

[g105b]

For example, on URL /shop/computers/apple/macbook-pro

There can be multiple dynamic path parts: page/shop/@shop-area/@brand/@item.html

Currently, the body gets the following classes:

• dir--page
• dir--page--shop
• dir--page--shop--_shop-area
• dir--page--shop--_shop-area--_brand
• dir--page--shop--_shop-area--_brand--_item
• uri--page--shop--_shop-area--_brand--_item

It would also be good to see the following classes, or something similar, so the individual dynamic pages can be referenced in CSS where appropriate:

• _shop-area--computers
• _brand--apple
• _item--macbook-pro

[g105b]

Can be implemented here: https://github.com/PhpGt/WebEngine/blob/64daaae7a9f6dec9f9935006c2ae930d76e0097a/src/Middleware/RequestHandler.php#L202-L213