Add ability to show emoji as icon

[kopach]

I would like emoji to be shown as main notification image. Something like that: notify -t 'Hello' -m 'My message' -i '👍'. Would it be possible?

I've discovered, that base64 image string works perfectly, but text of encoded image in base64 is very long. So, I've also tried to find any other cli tool which could convert emoji symbol to base64 image, so I could pass that into notify, but I haven't found any :(