feat: add support TPL in fields

[ngnix]

Add support TPL helper in cluster object to allow used gotemplate in chart values.

Tpl supported fields:

• cluster.initdb.database
• cluster.initdb.owner
• cluster.postgresql.parameters
• cluster.postgresql.pg_hba
• cluster.postgresql.pg_ident
• cluster.roles
• cluster.services
• cluster.serviceAccountTemplate.metadata.annotations
• cluster.serviceAccountTemplate.metadata.labels
• backups.s3.region
• backups.s3.bucket
• backups.s3.path
• endpointURL (S3/Azure/Google endpoint)
• destinationPath
• All dynamic paths (bucket, region, container, storage account)
• secret.name

Added example how to use TPL in subchart ( case when we used cluster chart as subchart).