Add support for indicator groups

Instead of looping through the scorecard's categories, we will get the
scorecard's indicator groups (the scorecard's indicators grouped by
category) and loop through these groups.
Nei, send heller inn en funksjon ala:
```js
scope.$watch(
    function () {
        return indicator.category;
    },
    function () {
        ...
    }
);
```
(da bruker watchen returverdien som alltid vil være fra det lokale scopet)