feat(testing-sdk): Refactor testing library to not use a running server (#344)

*Issue #, if available:*

*Description of changes:*

Currently the testing library spins up a whole server to simulate the
Lambda service. This is unnecessary overhead, and also can cause issues
with mocking, since its an extra dependency that customers need to avoid
mocking. Additionally, it can create issues due to port conflicts.

This change makes it so the server is now simulated using worker
communication instead of creating an actual socket.


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copy, and redistribute this contribution, under the terms of your
choice.

Author: anthonyting

package-lock.json

@@ -38,7 +38,6 @@
     "@tsconfig/node20": "^20.1.5",
     "@types/argparse": "^2.0.17",
     "@types/aws-lambda": "^8.10.150",
-    "@types/express": "^5.0.2",
     "@types/jest": "^30.0.0",
     "@types/morgan": "^1.9.10",
     "@types/supertest": "^6.0.3",

package.json

@@ -42,14 +42,12 @@
     "@eslint/compat": "^1.3.0",
     "@eslint/js": "^9.29.0",
     "@types/aws-lambda": "^8.10.150",
-    "@types/express": "^5.0.2",
     "@types/morgan": "^1.9.10",
     "@types/sinonjs__fake-timers": "^15.0.1",
     "@types/supertest": "^6.0.3",
     "eslint": "^9.29.0",
     "eslint-config-prettier": "^10.1.5",
     "eslint-plugin-jest": "^29.0.1",
-    "express": "^5.1.0",
     "jest": "^30.0.3",
     "supertest": "^7.1.1",
     "tsx": "^4.20.5",
@@ -59,8 +57,7 @@
   "dependencies": {
     "@aws-sdk/client-lambda": "*",
     "@sinonjs/fake-timers": "^13.0.5",
-    "@smithy/smithy-client": "^4.9.1",
-    "express": "^5.1.0"
+    "@smithy/smithy-client": "^4.9.1"
   },
   "peerDependencies": {
     "@aws/durable-execution-sdk-js": "*"