BlockUI is not properly destroyed

[Axel-Latour]

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Current behavior
I'm trying to use the BlockUI component on a page. I've made a test :

• Add a BlockUI on a page, and set the "blocked" property to true. Don't set the target.
• When you go on that page, the component is displayed, the page is blocked.
• If you still want to access the menu of your application when a page is blocked, it's impossible. If you click on an element of the menu, the route changes, and the BlockUI component is still displayed. You can't access anymore to the BlockUI component and its "blocked" property.

For example, on the PrimeNG showcase :

• Set z-index property of the div with id #layout-sidebar to 1007 (the value must be superior to 1006)
• Change the route with the menu
• The BlockUI component is still present and you can't hide it anymore...

Expected behavior

When I change route, the BlockUI should disappear. It seems that it's currently added to the body of the page, when target is undefined. Maybe add it to the current component, so when the user changes route, the component is destroyed and the BlockUI too ?