Ability to change implementation of Dialog/Popup

[igordmn]

Compose 1.1.1

Currently, when we use Dialog or Popup, we use hard-coded implementation:

• to open a Dialog we use native platform window
• to open a Popup we just draw the content of the popup over all other content on Canvas.

This prevents usage of Dialog/Popups in the other implementations of Compose:

• LWJGL
• ui-test

These implementations use ComposeScene under the hood. We need to invent some API, which allows to specify the factory for creating Dialogs/Popups, and pass it via ComposeScene constructor, or as a CompositionLocal.

[AlexeyTsvetkov]

A relevant issue https://github.com/JetBrains/compose-multiplatform/issues/2924