Goal tracking improvements

We've made some exciting additions to the goal tracking:

1. You can now configure a limit for the number of times a goal is tracked:
   1. Every time
   2. Once per page view (for click events)
   3. Once per session

This helps make sure that the analytics reflect a relevant number of conversions in both campaigns and widgets.

Besides that, a new button was added to goals, showing whether a goal was fired previously, helping you check whether the goal is configured correctly.