feat: Add NATS integration support to the event system

- Added NATS package to dependencies
- Created Prisma schema models for NATS configuration
- Implemented NATS controller, router, and event management
- Updated instance controller and event manager to support NATS
- Added NATS configuration options in environment configuration
- Included NATS events in instance validation schema

src/api/integrations/event/event.schema.ts

@@ -16,6 +16,9 @@ export const eventSchema: JSONSchema7 = {
     rabbitmq: {
       $ref: '#/$defs/event',
     },
+    nats: {
+      $ref: '#/$defs/event',
+    },
     sqs: {
       $ref: '#/$defs/event',
     },