Draft: Add Spark Structured Streaming based Benchmarks

This merge request includes Spark Structured Streaming benchmarks for use-cases 1 to 3. Furthermore, all necessary resources for execution with Theodolite on a Kubernetes cluster are included.

theodolite-benchmarks/definitions/uc1-spark/resources/ingress-dev.yaml

+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: http-ingress
+  annotations:
+    kubernetes.io/ingress.class: public
+    # nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
+spec:
+  rules:
+    # - host: spark-kubernetes
+  - http:
+      paths:
+      - path: /web
+        pathType: Prefix
+        backend:
+          service:
+            name: spark-master
+            port:
+              number:  8080
+      - path: /backend
+        pathType: Prefix
+        backend:
+          service:
+            name: spark-master
+            port:
+              number: 7077