Moves ProcessChooser and RunningProcessesModel to LibGUI and
generalizes their construction for use by other apps. Updates
Profiler to reflect the change and use its new icons.
ControlBoxButton consolidates the paint_event for buttons
used in composite box widgets like ComboBox and SpinBox. Its
button bitmaps are built with create_from_ascii like WindowFrame
and ScrollBar controls, making theming more uniform.
Widgets can now opt in to emoji input via set_accepts_emoji_input().
If the focused widget accepts emoji input, we'll pop up a simple dialog
with all the available emojis as clickable buttons.
You can press escape if you change your mind and don't want an emoji.
This UI layout definitely will not scale as we add more emojis, but it
works for the moment, and we can adapt it as we go. Pretty cool! :^)
