Add frontend speed test application and server setup

* Introduced a new HTML frontend for network speed testing with a responsive UI
* Implemented backend server functionality to serve the frontend and handle speed test APIs
* Added speed test logic for downloading and uploading data, including progress tracking and result validation
* Created README-SPEEDTEST.md for documentation on application architecture, setup, and usage.
* Updated package.json to include necessary scripts and dependencies for development and testing

src/repositories/InMemoryRequestRepository.ts

@@ -0,0 +1,19 @@
+import type { IRequestRepository } from '../core/interfaces/IRequestRepository';
+import type { SpeedTestContext } from '../core/domain/SpeedTestTypes';
+
+export class InMemoryRequestRepository implements IRequestRepository {
+  private readonly _storage: Record<string, SpeedTestContext> = {};
+
+  save(id: string, context: SpeedTestContext): void {
+    this._storage[id] = context;
+  }
+
+  get(id: string): SpeedTestContext | undefined {
+    return this._storage[id];
+  }
+
+  delete(id: string): void {
+    delete this._storage[id];
+  }
+}
+