Add moderation warnings (#9519)

* Add moderation warnings

Replace individual routes for disabling, silencing, and suspending
a user, as well as the report update route, with a unified account
action controller that allows you to select an action (none,
disable, silence, suspend) as well as whether it should generate an
e-mail notification with optional custom text. That notification,
with the optional custom text, is saved as a warning.

Additionally, there are warning presets you can configure to save
time when performing the above.

* Use Account#local_username_and_domain

db/migrate/20181213184704_create_account_warnings.rb

@@ -0,0 +1,12 @@
+class CreateAccountWarnings < ActiveRecord::Migration[5.2]
+  def change
+    create_table :account_warnings do |t|
+      t.belongs_to :account, foreign_key: { on_delete: :nullify }
+      t.belongs_to :target_account, foreign_key: { to_table: 'accounts', on_delete: :cascade }
+      t.integer :action, null: false, default: 0
+      t.text :text, null: false, default: ''
+
+      t.timestamps
+    end
+  end
+end

db/migrate/20181213185533_create_account_warning_presets.rb

@@ -0,0 +1,9 @@
+class CreateAccountWarningPresets < ActiveRecord::Migration[5.2]
+  def change
+    create_table :account_warning_presets do |t|
+      t.text :text, null: false, default: ''
+
+      t.timestamps
+    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: 2018_12_07_011115) do
+ActiveRecord::Schema.define(version: 2018_12_13_185533) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -76,6 +76,23 @@ ActiveRecord::Schema.define(version: 2018_12_07_011115) do
     t.index ["tag_id"], name: "index_account_tag_stats_on_tag_id", unique: true
   end
 
+  create_table "account_warning_presets", force: :cascade do |t|
+    t.text "text", default: "", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  create_table "account_warnings", force: :cascade do |t|
+    t.bigint "account_id"
+    t.bigint "target_account_id"
+    t.integer "action", default: 0, null: false
+    t.text "text", default: "", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id"], name: "index_account_warnings_on_account_id"
+    t.index ["target_account_id"], name: "index_account_warnings_on_target_account_id"
+  end
+
   create_table "accounts", force: :cascade do |t|
     t.string "username", default: "", null: false
     t.string "domain"
@@ -656,6 +673,8 @@ ActiveRecord::Schema.define(version: 2018_12_07_011115) do
   add_foreign_key "account_pins", "accounts", on_delete: :cascade
   add_foreign_key "account_stats", "accounts", on_delete: :cascade
   add_foreign_key "account_tag_stats", "tags", on_delete: :cascade
+  add_foreign_key "account_warnings", "accounts", column: "target_account_id", on_delete: :cascade
+  add_foreign_key "account_warnings", "accounts", on_delete: :nullify
   add_foreign_key "accounts", "accounts", column: "moved_to_account_id", on_delete: :nullify
   add_foreign_key "admin_action_logs", "accounts", on_delete: :cascade
   add_foreign_key "backups", "users", on_delete: :nullify