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
BasicUserSerializer contains enough information for the badges page,
while UserSerializer issues ~100 SQL queries on the fly when serializing
the field without preloading.
Bianca Nenciu
Joffrey JAFFEUX
Sam Saffron
Kyle Zhao
Guo Xiang Tan