chore: Refactor RefreshOauthTokenService to improve readability (#8820)

- Added a trait called microsoft_email for the Channel::Email factory.
- Rewrote the logic to make it simple to understand
- Rewrote the specs for readability

spec/factories/channel/channel_email.rb

@@ -8,5 +8,22 @@ FactoryBot.define do
     after(:create) do |channel_email|
       create(:inbox, channel: channel_email, account: channel_email.account)
     end
+
+    trait :microsoft_email do
+      imap_enabled { true }
+      imap_address { 'outlook.office365.com' }
+      imap_port { 993 }
+      imap_login { 'email@example.com' }
+      imap_password { '' }
+      imap_enable_ssl { true }
+      provider_config do
+        {
+          expires_on: Time.zone.now + 3600,
+          access_token: SecureRandom.hex,
+          refresh_token: SecureRandom.hex
+        }
+      end
+      provider { 'microsoft' }
+    end
   end
 end