Currently the process of adding a custom image to badge is quite clunky; you have to upload your image to a topic, and then copy the image URL and pasting it in a text field. Besides being clucky, if the topic or post that contains the image is deleted, the image will be garbage-collected in a few days and the badge will lose the image because the application is not that the image is referenced by a badge.
This commit improves that by adding a proper image uploader widget for badge images.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
FIX: fallback to description if badge long description is missing
Also moves all badge localization into server.en, this slims the client down
serializers pass down localized names/descriptions/long descriptions
