Allow Editing of Image Evidence

[jkennedyvz]

For some workflows with ashirt, and operator might need to capture a large area, and then annotate the image to draw attention to important parts.

Ashirt should perhaps have a separate hotkey combo for taking a screen, opening it in a system image editor for annotation, and then finally forward to ashirt-server.

[JoelAtDeluxe]

I think this can be accomplished via changing what the command is for taking screenshots. I'll research this, but I think there are options to do this in macos in particular. i need to research the others

[jkennedyvz]

Let's also try to consider how this might impact the windows 10 side - windows has a screenshot editing application, but not one that conforms to our current requirements for immediate save.