Support hosting the Widget Previewer in Android Studio / Intellij

[bkonyi]

Initial support has landed in VSCode and looks like this:

Screen.Recording.2025-09-18.at.9.12.18.AM.mov

To match this, we need to be able to:

• Launch and manage the lifecycle of flutter widget-preview start --web-server.
• Open an iframe or browser within Intellij to view the preview application.
• Send IDE navigation events via the Editor DTD service to update which previews are visible based on the currently selected file.

[helin24]

@bkonyi

1. What is the min flutter SDK version that supports this?
2. Is there an icon that would be appropriate for our tool menu bar?