Allow PixelPicker to be AppleScript'ed

[acheronfail]

It would be nice to automate the picker with AppleScript, namely in the following ways:

• [ ] activate the picker
• [ ] move the picker to x, y coords (and optionally select the pixel)
• [ ] copy the color in a given format

For reference:

• https://developer.apple.com/library/content/documentation/AppleScript/Conceptual/AppleScriptX/Concepts/scriptable_apps.html
• https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/ScriptableCocoaApplications/SApps_about_apps/SAppsAboutApps.html#//apple_ref/doc/uid/TP40001976
• https://www.raywenderlich.com/133007/making-mac-app-scriptable-tutorial