Finishes the refactoring started in c1bbd8d. The goal of the refactoring is
to change the argument to get_realm from a Realm.domain to a
Realm.string_id. The steps were
* Add a new function, get_realm_by_string_id.
* Change all calls to get_realm to use get_realm_by_string_id instead.
* Remove get_realm.
* (This commit) Rename get_realm_by_string_id to get_realm.
Part of a larger migration to remove the Realm.domain field entirely.
Move commands related to stats collection and reporting from
zilencer to analytics. To do this, we had to make "analytics"
officially an app.
(imported from commit 63ef6c68d1b1ebb5043ee4aca999aa209e7f494d)