IDE-73 Add camera picture to screenshot

[Jr9992]

Merges camera picture into screenshot if screenshot is taken while the camera is active.

• add ScreenshotUtils.kt
• change logic in ScreenshotSaver.kt
• add functions to CameraManager.kt
• add logic to StageActivity.java
• add logic to StageListener.java
• change ScreenshotSaverTest.kt

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