Add panelClass to overlay components

[maherma-adg]

With the use of Teleport in Dropdown and MultiSelect components, any personalization based in scope is lost because panel is translated to body root, outside the scoped component.

Solution proposed is to add a "panelClass" property in the same way as Calendar component.

a PR can be provided if this solutions is accepted

Regards,
Manuel

[maherma-adg]

Found this (#1028 (comment)) that look the same problem

[afonic]

I think adding panelClass like @maherma-adg suggested is not going to solve all issues regarding when you need the
component to attach to a certain element. Adding a prop to disable it would solve this.

Besides, losing stying sometimes an Autocomplete component can be inside a dynamic component (like a search Dropdown) and closing that component flashes the dropdown in the top left corner for a few ms.

[LadislavBohm]

This is also issue for all dialogs now.

[cagataycivici]

I've added panel class where necessary, dialogs have class already. Note that original issue is not caused by PrimeVue, we're just using Teleport API, CSS scoping and moving the element to body is done by Vue.