chore: Campaign ID migration for existing accounts (#2189)

* chore: Campaign ID migration for existing accounts

* chore: update factory

* chore: minor fixes

* chore: fixes

spec/factories/campaigns.rb

@@ -3,7 +3,7 @@
 FactoryBot.define do
   factory :campaign do
     sequence(:title) { |n| "Campaign #{n}" }
-    sequence(:content) { |n| "Campaign content #{n}" }
+    sequence(:message) { |n| "Campaign message #{n}" }
     after(:build) do |campaign|
       campaign.account ||= create(:account)
       campaign.inbox ||= create(