CCM-13475: add input transformation

Author: lapenna-bjss

infrastructure/terraform/components/dl/cloudwatch_event_rule_letter_prepared.tf

@@ -16,4 +16,6 @@ resource "aws_cloudwatch_event_target" "letter-prepared-main-bus-target" {
   rule           = aws_cloudwatch_event_rule.letter_prepared.name
   arn            = module.eventpub.sns_topic.arn
   event_bus_name = aws_cloudwatch_event_bus.main.name
+
+  input_path = "$.detail"
 }

lambdas/print-sender-lambda/src/app/print-sender.ts

@@ -29,6 +29,7 @@ export class PrintSender {
           'https://notify.nhs.uk/cloudevents/schemas/letter-rendering/letter-request.prepared.1.1.5.schema.json',
         source: `/data-plane/digital-letters/${this.accountType}/${this.environment}`,
         specversion: '1.0',
+        datacontenttype: 'application/json',
         traceparent: item.traceparent,
         severitynumber: item.severitynumber,
         severitytext: 'INFO',