feat: service.{http,ssh}.loadBalancerClass (#640)

### Description of the change

Introduce `service.{http,ssh}.loadBalancerClass`

### Benefits

Feature was not supported before. This is required if your cluster has multiple loadBalancer options and you want to select one

### Possible drawbacks

More yaml.

### Checklist

- [x] Parameters are documented in the `values.yaml` and added to the `README.md` using [readme-generator-for-helm](https://github.com/bitnami-labs/readme-generator-for-helm)
- [x] Templating unittests are added

Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/640
Reviewed-by: pat-s <pat-s@noreply.gitea.com>
Co-authored-by: Karitham <kar@karitham.dev>
Co-committed-by: Karitham <kar@karitham.dev>

unittests/deployment/svc-configuration.yaml

@@ -49,3 +49,70 @@ tests:
     asserts:
       - exists:
           path: metadata.labels["app"]
+
+  - it: render service.ssh.loadBalancerClass if set and type is LoadBalancer
+    template: templates/gitea/ssh-svc.yaml
+    set:
+      service:
+        ssh:
+          loadBalancerClass: "example.com/class"
+          type: LoadBalancer
+          loadBalancerIP: "1.2.3.4"
+          loadBalancerSourceRanges:
+            - "1.2.3.4/32"
+            - "5.6.7.8/32"
+    asserts:
+      - equal:
+          path: spec.loadBalancerClass
+          value: "example.com/class"
+      - equal:
+          path: spec.loadBalancerIP
+          value: "1.2.3.4"
+      - equal:
+          path: spec.loadBalancerSourceRanges
+          value: ["1.2.3.4/32", "5.6.7.8/32"]
+
+  - it: does not render when loadbalancer properties are set but type is not loadBalancerClass
+    template: templates/gitea/http-svc.yaml
+    set:
+      service:
+        http:
+          type: ClusterIP
+          loadBalancerClass: "example.com/class"
+          loadBalancerIP: "1.2.3.4"
+          loadBalancerSourceRanges:
+            - "1.2.3.4/32"
+            - "5.6.7.8/32"
+    asserts:
+      - notExists:
+          path: spec.loadBalancerClass
+      - notExists:
+          path: spec.loadBalancerIP
+      - notExists:
+          path: spec.loadBalancerSourceRanges
+
+  - it: does not render loadBalancerClass by default even when type is LoadBalancer
+    template: templates/gitea/http-svc.yaml
+    set:
+      service:
+        http:
+          type: LoadBalancer
+          loadBalancerIP: "1.2.3.4"
+    asserts:
+      - notExists:
+          path: spec.loadBalancerClass
+      - equal:
+          path: spec.loadBalancerIP
+          value: "1.2.3.4"
+
+  - it: both ssh and http services exist
+    templates:
+      - templates/gitea/ssh-svc.yaml
+      - templates/gitea/http-svc.yaml
+    asserts:
+      - matchRegex:
+          path: metadata.name
+          pattern: "^gitea-unittests-(?:ssh|http)$"
+      - matchRegex:
+          path: spec.ports[0].name
+          pattern: "^(?:ssh|http)$"