Account deletion (#3728)

* Add form for account deletion

* If avatar or header are gone from source, remove them

* Add option to have SuspendAccountService remove user record, add tests

* Exclude suspended accounts from search

app/workers/admin/suspension_worker.rb

@@ -5,7 +5,7 @@ class Admin::SuspensionWorker
 
   sidekiq_options queue: 'pull'
 
-  def perform(account_id)
-    SuspendAccountService.new.call(Account.find(account_id))
+  def perform(account_id, remove_user = false)
+    SuspendAccountService.new.call(Account.find(account_id), remove_user)
   end
 end