feat: Email signature API support (#3874)

db/migrate/20220131081750_add_email_signature_to_user.rb

@@ -0,0 +1,8 @@
+class AddEmailSignatureToUser < ActiveRecord::Migration[6.1]
+  def change
+    change_table :users, bulk: true do |t|
+      t.boolean :message_signature_enabled, null: false, default: false
+      t.text :message_signature, null: true
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2022_01_21_055444) do
+ActiveRecord::Schema.define(version: 2022_01_31_081750) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_stat_statements"
@@ -747,6 +747,8 @@ ActiveRecord::Schema.define(version: 2022_01_21_055444) do
     t.jsonb "ui_settings", default: {}
     t.jsonb "custom_attributes", default: {}
     t.string "type"
+    t.boolean "message_signature_enabled", default: false, null: false
+    t.text "message_signature"
     t.index ["email"], name: "index_users_on_email"
     t.index ["pubsub_token"], name: "index_users_on_pubsub_token", unique: true
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true