Add account migration UI (#11846)

Fix #10736

- Change data export to be available for non-functional accounts
- Change non-functional accounts to include redirecting accounts

app/controllers/settings/exports_controller.rb

@@ -6,6 +6,9 @@ class Settings::ExportsController < Settings::BaseController
   layout 'admin'
 
   before_action :authenticate_user!
+  before_action :require_not_suspended!
+
+  skip_before_action :require_functional!
 
   def show
     @export  = Export.new(current_account)
@@ -34,4 +37,8 @@ class Settings::ExportsController < Settings::BaseController
   def lock_options
     { redis: Redis.current, key: "backup:#{current_user.id}" }
   end
+
+  def require_not_suspended!
+    forbidden if current_account.suspended?
+  end
 end