fix: Use visibility server when defining visibility config

[bakjos]

What was changed

Why?

When the default store uses cassandra and the visibility store sql the config was not including the sql part

Checklist

1. Closes

2. How was this tested:

   Using the following values

server:
  replicaCount: 1
  config:
    persistence:
      default:
        cassandra:
          hosts:
            - cassandra
          port: 9042
      visibility:
        driver: "sql"
        sql:
          driver: "postgres"
          host: "postgres"
          port: 5432
          database: "temporal_visibility"
          user: "postgres"
          password: "postgres"
          maxConns: 20
          maxConnLifetime: "1h"

3. Any docs updates needed?

[CLAassistant]

All committers have signed the CLA.

[robholland]

Thanks :)