Introduce CRD for Iceberg table maintanance

As a Trino Iceberg user I want to define a CR that allows me to regularly run maintenance actions on my tables.

• Come up with a CRD
• Figure out how to authenticate against Trino Cluster, e.g. always create a k8s Secret for a service user and add that into the authentication chain using Password file authentication as well as mount it into the k8s CronJob

Should

• Allow to run at whole schema, which iterates through tables
• Emit Prometheus metrics so we can alert on failures and have a Dashboard

Could

• Prometheus alters
• Grafana dashboard with e.g. files compacted, bytes and rows read/written

One possible solution would be to create a k8s CronJob for every maintenance CR.
CRD could look something like

spec:
  target:
    catalog: lakehouse
    schema: default
    table: my_table # Optional
  schedule:
    interval: 24h # using new Duration struct
    # OR
    cronExpression: XXX
  actions:
    - name: optimize
      fileSizeThreshold: 100MB # optional, otherwise let trino use it's internal default
    - name: expire_snapshots
      retentionThreshold: 7d # optional, otherwise let trino use it's internal default
    - name: remove_orphan_files
      # Document: The value for retention_threshold must be higher than or equal to iceberg.remove_orphan_files.min-retention in the catalog otherwise the procedure fails with a similar message: Retention specified (1.00d) is shorter than the minimum retention configured in the system (7.00d)
      retentionThreshold: 7d # optional, otherwise let trino use it's internal default

Start with the proposed CRD shape and the linked Trino Iceberg maintenance actions documentation. Define what completion means across scheduling maintenance for tables or schemas, authenticating to Trino, handling retention settings, and exposing Prometheus metrics; the issue also mentions Kubernetes CronJobs, alerts, and a Grafana dashboard.