fix: use pod FQDN for replica-announce-ip and sentinel announce-ip

[pcamminadi]

Description

When running Redis Replication with Sentinel behind a service mesh (e.g. Istio), pod IPs can be non-routable loopback addresses (such as 127.0.0.6). This causes two problems:

1. Sentinel announce-ip was set to the master's address — the existing code used the ip variable (which holds the master's address) for sentinel announce-ip, instead of the sentinel pod's own address.
2. Replicas had no replica-announce-ip — in replication/standalone mode, replicas never announced their address, so sentinels tracked them by their ephemeral (and potentially non-routable) pod IP.

This PR:

• Adds resolveHostnames and announceHostnames fields to RedisReplicationSpec, matching the existing fields on SentinelConfig.
• When both are set to "yes", replicas set replica-announce-ip to their pod FQDN.
• Fixes the sentinel bootstrap to resolve its own FQDN for sentinel announce-ip instead of incorrectly using the master's address.
• Propagates the new fields as RESOLVE_HOSTNAMES / ANNOUNCE_HOSTNAMES env vars to the Redis replication container.
• Exposes the new fields in the redis-replication Helm chart.

Fixes #1635

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• Tests have been added/modified and all tests pass.
• Functionality/bugs have been confirmed to be unchanged or fixed.
• I have performed a self-review of my own code.
• Documentation has been updated or added where necessary.

Additional Context

• Default values ("no") preserve existing behavior — no env vars are injected unless the user explicitly sets the fields to "yes".
• The sentinel's resolveHostnames/announceHostnames fields in SentinelConfig (common types) already existed; this PR only adds them at the RedisReplicationSpec level so the Redis agent can also use them.
• Unit tests added for generateRedisReplicationContainerParams covering env var injection for all combinations of resolveHostnames/announceHostnames values, including appending to existing env vars.
• Tested on a Kubernetes cluster with Istio service mesh, confirming that sentinels and replicas correctly announce their FQDNs and failover works as expected.