This is a preparatory commit for using isort for sorting all of our
imports, merging changes to files where we can easily review the
changes as something we're happy with.
These are also files with relatively little active development, which
means we don't expect much merge conflict risk from these changes.
When using our EMAIL_ADDRESS_VISIBILITY_ADMINS feature, we were
apparently creating bot users with different email and delivery_email
properties, due to effectively an oversight in how the code was
written (the initial migration handled bots correctly, but not bots
created after the transition).
Following the refactor in the last commit, the fix for this is just
adding the missing conditional, a test, and a database migration to
fix any incorrectly created bots leaked previously.
Tim Abbott