Make sure event feed registered indication is correct

Before there was no check whether or not the events needs registration. Now there is.

Also, the CSS wasn't correct. It should be now. I also translated the listview JavaScript.

Plus: I changed the icon colours to dark grey/magenta because red/green is not really clear.

Homepage:

Before:

1. Open the homepage
2. Notice that you're (not) registered for an event.
3. The circle is located in the vertical center of the card
4. The circle is red (not registered) or green (registered).

After:

1. Open the homepage
2. Notice that you're (not) registered for an event.
3. The circle is located in the top-right of the card
4. The circle is grey (not registered) or magenta (registered).

Events list page:

Before:

1. Open the agenda
2. Click on 'list' for the listview
3. Notice that you're (not) registered for an event.
4. The circle is located in the vertical center of the row.
5. The circle is red (not registered) or green (registered).
6. When you expand the row the circle is in the vertical center of the whole big expanded row.
7. All events without registration have circles

After:

1. Open the agenda
2. Click on 'list' for the listview
3. Notice that you're (not) registered for an event.
4. The circle is located in the vertical center of the row.
5. The circle is green (not registered) or red (registered).
6. When you expand the row the circle is still in the same place as it was before expanding.
7. All events without registration do not have circles.