chore: Fetch one destination instead of all (#4371)

* fix some tests

* fix all tests except caching

* fix last tests

* fix http-client tests

* improve default mocking for 404

* add changelog

* fix mail tests

* fix request builder mocks

* Remove nock from dependencies

* fix integration tests

* remove unused function

* remove unused mock function

* refactor tests and fix tsconfig

* improve changelog message

* rename

* fix typo

.changeset/funny-weeks-warn.md

@@ -0,0 +1,6 @@
+---
+'@sap-cloud-sdk/connectivity': minor
+---
+
+[Compatibility Note] The SAP Cloud SDK used to get all subaccount and instance destinations, that are available with your JWT (without potentially required token retrieval), through two requests to the destination service (`/subaccountDestinations` and `/instanceDestinations`). While this approach can have advantages when caching, it can cause severe performance issues without caching. Therefore, from now on, only one destination is retrieved per requested destination through `/destinations`.
+You can no longer rely on the SDK to automatically cache all destinations on the first request. If needed, you can call `getAllDestinationsFromDestinationService()` with cache enabled instead.

.changeset/gorgeous-dogs-beam.md

@@ -0,0 +1,5 @@
+---
+'@sap-cloud-sdk/connectivity': minor
+---
+
+[Improvement] Retrieve only one destination per requested destination instead of all subaccount and instance destinations. (See compatibility notes.)

packages/connectivity/src/scp-cf/circuit-breaker.spec.ts

@@ -8,7 +8,7 @@ import {
 } from '../../../../test-resources/test/test-util/environment-mocks';
 import { privateKey } from '../../../../test-resources/test/test-util/keys';
 import { getClientCredentialsToken } from './xsuaa-service';
-import { fetchDestination } from './destination';
+import { fetchDestinationWithTokenRetrieval } from './destination';
 
 const jwt = jwt123.sign(
   JSON.stringify({ user_id: 'user', zid: 'tenant' }),
@@ -30,7 +30,7 @@ describe('circuit breaker', () => {
 
   it('opens after 50% failed request attempts (with at least 10 recorded requests) for destination service', async () => {
     const request = () =>
-      fetchDestination(destinationServiceUri, jwt, {
+      fetchDestinationWithTokenRetrieval(destinationServiceUri, jwt, {
         destinationName: 'FINAL-DESTINATION'
       });