Visualize number of Days Participated in Study

[casaout]

For studies, it might be valuable to visualize to participants how many days they've participated so far, given some kind of metric.

This idea is inspired by AwarenessBar's visualization of study-related information

Tasks:

• create a new study config setting displayDaysParticipated (default: true)
  • add a comment to point to the method and docu that calculates the measure, so it can easily be adapted (+ update in the documentation for researchers)
• create a measure daysParticipated that is updated on a daily (?) basis
  • as a simple default measure, we suggest to count as a study day if (a) at least one experience sampling response was given (if enabled) and (b) there are at least 60 user input entries (indicating 60+ minutes of activity)
• visualize the number of days in the context menu: Days participated: {number}
• also, while we're at it, display the subject id in the context menu: Subject Id: {id} and a add a Copy Subject Id button