feat: introduce Result Service using Lakekeeper as REST catalog for Iceberg - Kubernetes deployment

[mengw15]

What changes were proposed in this PR?

This is PR 4 of a decomposed series from #4242, adding Lakekeeper integration to the Kubernetes/Helm deployment.

Files changed:

• bin/k8s/Chart.yaml: added Lakekeeper Helm chart dependency (lakekeeper v0.9.0)
• bin/k8s/values.yaml: added Lakekeeper and lakekeeperInit configuration (warehouse name, S3 bucket, region, default
  project)
• bin/k8s/templates/lakekeeper-init-job.yaml (new): Kubernetes Job that bootstraps Lakekeeper — creates MinIO bucket,
  default project, and warehouse
• bin/k8s/templates/external-names.yaml: added Lakekeeper ExternalName service for computing-unit-pool namespace access
• bin/k8s/templates/workflow-computing-unit-manager-deployment.yaml: switched from Postgres catalog to REST catalog env
  vars; added wait-lakekeeper init container
• bin/k8s/templates/webserver-deployment.yaml: added REST catalog env vars
• bin/k8s/templates/postgresql-init-script-config.yaml: added Lakekeeper database initialization
• bin/k8s/files/texera_lakekeeper.sql (new): symlink to sql/texera_lakekeeper.sql

Any related issues, documentation, discussions?

Part of #4126. Depends on #4272 (catalog migration).

How was this PR tested?

Manually tested

Was this PR authored or co-authored using generative AI tooling?

co-authored with claude