The metastore offers replicas > 1 but no HA ist configured

Currently, the Hive metastore can be configured with multiple replicas > 1 per role group. This results in the feeling for high availability. The service discovery to offers multiple FQDN's to different (and completely unrelated) metastores (https://github.com/stackabletech/hive-operator/pull/145).

We should consolidate the behavior and have two options:

1. Fix replicas to 1 and offer a warning if set > 1. Add in the documentation that metastores from different rolegroups do not offer HA or interact with each other
2. Implement HA for the metastore (e.g. using ZooKeeperTokenStore)?

TODO: They all share the same database, Metastore should still be stateless, ZK discovery does exist but not sure what uses that. This is for Jim to research

Empieza revisando el comportamiento actual de la réplica del metastore de Hive descrito en issue #154 y el contexto del descubrimiento de servicios en pull request #145. Investiga si la base de datos compartida y ZooKeeperTokenStore admiten HA real y, después, elige entre limitar las réplicas a una con la documentación correspondiente o implementar HA; se considerará terminado cuando el comportamiento seleccionado esté implementado y documentado.