Add e-mail-based sign in challenge for users with disabled 2FA (#14013)

db/migrate/20200608113046_add_sign_in_token_to_users.rb

@@ -0,0 +1,6 @@
+class AddSignInTokenToUsers < ActiveRecord::Migration[5.2]
+  def change
+    add_column :users, :sign_in_token, :string
+    add_column :users, :sign_in_token_sent_at, :datetime
+  end
+end

db/schema.rb

@@ -10,7 +10,8 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_06_05_155027) do
+ActiveRecord::Schema.define(version: 2020_06_08_113046) do
+
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -869,6 +870,8 @@ ActiveRecord::Schema.define(version: 2020_06_05_155027) do
     t.string "chosen_languages", array: true
     t.bigint "created_by_application_id"
     t.boolean "approved", default: true, null: false
+    t.string "sign_in_token"
+    t.datetime "sign_in_token_sent_at"
     t.index ["account_id"], name: "index_users_on_account_id"
     t.index ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true
     t.index ["created_by_application_id"], name: "index_users_on_created_by_application_id"