As a user, I can choose other property then "Priority" to group Requirements in the Coverage Charts

Currently, only the priority property is used to group requirements in the Coverage Charts. It should be possible for the user to choose the property to group in the chart configuration.

Possible grouping properties are:

• Component
• Status

This also affects the Requirement Coverage Gadgets.

On the Daily Historic Coverage Chart, the number of select options is limited to 3. In this case, only the first 2 options are visible. All remaining options are grouped into "Other".