fix: add srCheckPassword param to support new postgresql-ha stream replication check requirements (#894)

### Add new 'srCheckPassword' postgresql-ha value to support new postgresql-ha stream replication check requirements

Per Bitnami's [documentation](https://github.com/bitnami/charts/tree/main/bitnami/postgresql-ha#to-1600), a new 'sr_check_user' now exists for the purpose of pgpool preforming stream replication checking.

### Benefits

This change allows customizing that role's password by overriding Bitnami's chart value.

### Possible drawbacks

None that I'm aware of.

### Applicable issues

- Fixes #888

### Additional information

Per #888, the Bitnami PR where customizable stream reapplication check credentials were introduced is https://github.com/bitnami/charts/pull/33552

### Checklist

<!-- [Place an '[X]' (no spaces) in all applicable fields. Please remove unrelated fields.] -->

- [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] Helm templating unittests are added (required when changing anything in `templates` folder)

Reviewed-on: https://gitea.com/gitea/helm-gitea/pulls/894
Reviewed-by: pat-s <pat-s@noreply.gitea.com>
Co-authored-by: Jade Deane <jade.deane@gmail.com>
Co-committed-by: Jade Deane <jade.deane@gmail.com>

unittests/helm/dependency-checks/customization-integrity-postgresql-ha.yaml

@@ -18,6 +18,7 @@ set:
       password: custom-password-overwritten-by-global-postgresql-password
     pgpool:
       adminPassword: custom-password-pgpool
+      srCheckPassword: custom-password-sr-check
     service:
       ports:
         postgresql: 1234
@@ -75,6 +76,13 @@ tests:
         equal:
           path: data["admin-password"]
           value: "Y3VzdG9tLXBhc3N3b3JkLXBncG9vbA=="
+  - it: "[postgresql-ha] pgpool.srCheckPassword is applied as expected"
+    template: charts/postgresql-ha/templates/pgpool/secrets.yaml
+    asserts:
+      - documentIndex: 0
+        equal:
+          path: data["sr-check-password"]
+          value: "Y3VzdG9tLXBhc3N3b3JkLXNyLWNoZWNr"
   - it: "[postgresql-ha] persistence.size is applied as expected"
     template: charts/postgresql-ha/templates/postgresql/statefulset.yaml
     asserts: