[Feature Request] Multiple hosts for postgres12_pgx

[vovcyan]

Describe the solution you'd like

postgres12_pgx plugin can work with multiple PostgreSQL hosts but in helm chart there is an option to pass only 1 host. Because of dynamic changes in random moment of master/replica roles of hosts in Postgres cluster (or due maintenance) there is no option specify only master host in config.

Current solution server-configmap.yaml#L35 supports only 1 host for SQL persistence and visibility:

connectAddr: "{{ include "temporal.persistence.sql.host" (list $ "default") }}:{{ include "temporal.persistence.sql.port" (list $ "default") }}"

Example of passing multiple hosts for postgres12_pgx

...
pluginName: "postgres12_pgx"
databaseName: "main"
connectAddr: "a-host.com:5432,b-host.com:5432,c-host.com:5432"
connectProtocol: "tcp"
...

Additional context

I can help with PR

[vovcyan]

@robholland