Add moderation note (#5240)

* Add moderation note

* Add frozen_string_literal

* Make rspec pass

app/controllers/admin/account_moderation_notes_controller.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class Admin::AccountModerationNotesController < Admin::BaseController
+  def create
+    @account_moderation_note = current_account.account_moderation_notes.new(resource_params)
+    if @account_moderation_note.save
+      @target_account = @account_moderation_note.target_account
+      redirect_to admin_account_path(@target_account.id), notice: I18n.t('admin.account_moderation_notes.created_msg')
+    else
+      @account = @account_moderation_note.target_account
+      @moderation_notes = @account.targeted_moderation_notes.latest
+      render template: 'admin/accounts/show'
+    end
+  end
+
+  def destroy
+    @account_moderation_note = AccountModerationNote.find(params[:id])
+    @target_account = @account_moderation_note.target_account
+    @account_moderation_note.destroy
+    redirect_to admin_account_path(@target_account.id), notice: I18n.t('admin.account_moderation_notes.destroyed_msg')
+  end
+
+  private
+
+  def resource_params
+    params.require(:account_moderation_note).permit(
+      :content,
+      :target_account_id
+    )
+  end
+end