rfc Improve subscription images

[Werner]

The current forum badges for subscriptions are very simplistic. They could be a bit fancier. Not much, just a bit so they do not look that crude anymore

This is what I came up with

 

 

 

 

In first place I though about some transparency but since there are multiple themes including a dark one available it needs to look decent on both.

Also thinking about adding some further icons in the same design but they are not to be revealed to the public yet