Minor refactoring, error returns and e2e testing suite

.github/workflows/e2e.yml

@@ -0,0 +1,21 @@
+name: E2E Tests
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  e2e-tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+
+    - name: Run E2E Tests
+      run: |
+        cd test/e2e
+        docker compose up --build --abort-on-container-exit --exit-code-from tester