IssueTracker

Description:
Allow Composable to be extracted into a ImageBitmap or maybe a new Composable that allows its inner children to be captured

Use Case:
Capturing a part of UI is crucial for simple image-editing (Drawing on image, simple filters,..) or video-generating application (use with MediaCodec and MediaMuxer), it's the main logic for these applications. I think in the future, sooner or later, Compose should has its own way of extracting UI content instead of depending on the legacy Android View. This also benefit the Compose Multiplatform users (like me) whom can't utilize the Android View