5.3.26

Add DirectDebit to GoCardlessPaymentDriver
Increase rate limit for postmark
Fix language of subscription purchase
Minor fixes for marking an invoice as sent
Add SEPA to Gateway
Fixes for Swagger + Group Settings Documents
Set default design to Clean
Reset all counters to 1 after company purge
Refactor for backup storage location
Fixes for SystemLogger
Fixes for PayPal email
Stripe BACS-Support thanks @LarsK1
Stripe ACSS-Support thanks @LarsK1
Added EPS-Test
Minor fixes for test PDF
Mark as sent when we get to the payment screen
Fixes for contact authentication + viewed entity notifications
Custom validation rule for amount
Throw exception on paytrace failure
Tests for custom validation rules