Add support for Redis sentinels

[scottfrederick]

An issue in Spring Cloud Connectors gives examples of two service brokers that provide sentinel connection details in service binding credentials.

[making]

Tanzu for Valkey now supports sentinels

The credentials format is like below:
https://docs.vmware.com/en/VMware-Tanzu-for-Valkey-on-Cloud-Foundry/4.0/valkey-tanzu-cloud-foundry/appdevs.html#check-availability-6

# schema for non-ha service-instances
{
  "host": "q-s0.redis-instance.ENVIRONMENT-NAME-services-subnet.service-instance-GUID.bosh",
  "password": YOUR-PASSWORD,
  "port": INSECURE-PORT-NUMBER,
  "tls_port": SECURE-PORT-NUMBER
}

# schema for ha service-instances
{
    "master_name": "redis-master",
    "password": YOUR-REDIS-PASSWORD,
    "port": INSECURE-REDIS-PORT-NUMBER,
    "sentinel_password": YOUR-SENTINEL-PASSWORD,
    "sentinels": [
      {"host": INSTANCE-1-HOSTNAME, "port": INSECURE-SENTINEL-PORT-NUMBER, "tls_port": SECURE-SENTINEL-PORT-NUMBER},
      {"host": INSTANCE-2-HOSTNAME, "port": INSECURE-SENTINEL-PORT-NUMBER, "tls_port": SECURE-SENTINEL-PORT-NUMBER},
      {"host": INSTANCE-3-HOSTNAME, "port": INSECURE-SENTINEL-PORT-NUMBER, "tls_port": SECURE-SENTINEL-PORT-NUMBER},
    ],
    "tls_port": SECURE-REDIS-PORT-NUMBER,
    "tls_versions": SUPPORTED_TLS_VERSIONS
}

Can you please support this format for sentinels?