ref(nestjs): Move decorators to folder (#13509)

Just moving the decorators to improve the structure of the nest SDK
package a bit.

Author: nicohrubec

packages/nestjs/src/cron-decorator.ts renamed to packages/nestjs/src/decorators/sentry-cron.ts

@@ -1,5 +1,5 @@
 import { captureException } from '@sentry/core';
-import { isExpectedError } from './helpers';
+import { isExpectedError } from '../helpers';
 
 /**
  * A decorator to wrap user-defined exception filters and add Sentry error reporting.

packages/nestjs/src/span-decorator.ts renamed to packages/nestjs/src/decorators/sentry-traced.ts

@@ -2,6 +2,6 @@ export * from '@sentry/node';
 
 export { init } from './sdk';
 
-export { SentryTraced } from './span-decorator';
-export { SentryCron } from './cron-decorator';
-export { WithSentry } from './error-decorator';
+export { SentryTraced } from './decorators/sentry-traced';
+export { SentryCron } from './decorators/sentry-cron';
+export { WithSentry } from './decorators/with-sentry';