Improvements to targets

[almarklein]

• Ability to set global targets (instead of per-tag).
• Ability to set separate day and week targets (at least for the global targets, perhaps also for the tag-targets).
• Track progress visually (a progress bar of sorts).
• Overview of the status of the defined goals. (Which tags have a time goal and how far away am I from the goal currently?)
• A visual "celebration" when a target has been reached.
• Maybe: negative goals for activities that you want to limit.
• Ability to set an absolute target that can be worked towards, instead of repeating it per week/day.
  • I suppose this can be mimicked by setting a yearly limit in many cases, but some of the behavior would be different, e.g. the work shown per day/week would be based on the remaining time, rather than simply dividing the total time by the time factor.

[almarklein]

The foundations for some of these changes have been made in #188. In particular, we can now store multiple targets per tag (but don't use it yet).

[Luzifer]

One small addition to this: Would be great to have a target per "work week"…

As an example:

• I'm working 40 hours / week (target: 40h / week)
• I'm only working Mon-Fri (5d / week)
• Today I worked 8:05 hours (so 5min overtime), the app tells me I've worked 2:22 overtime

[almarklein]

@Luzifer Good point!