Feature widget for count and positioners

This MR provide a way to display the content of a ct scan inside Flint. Plus a side widget to display the positioners from the current scan.

• Displays count values and units
  • Optionally divide the values by the integration time
• Display positioners name and values
  • Mode to select user/dial positions
• A menu allow to open this windows
  • The count widget will be open automatically we a ct is processing
  • The positioners widget have to be open manually.