Add automated TPU support and GCS integration in TPU v6 blueprint

[shubpal07]

This PR introduces two major enhancements for Cloud TPU users: it makes the core GKE modules "TPU-aware" for automated job creation and adds a new blueprint for TPU v6e with GCS integration.

1. Automated TPU Job Configuration:
   Problem: Deploying TPU jobs previously required manual manifest editing for resource requests, tolerations, and GKE Warden selectors.
   Solution: The gke-node-pool and gke-job-template modules have been refactored. A new internal tpu-definition module centralizes TPU logic, allowing the gke-job-template to automatically generate complete and correct manifests for TPU workloads via the use: directive, eliminating all manual steps.
2. New GCS + TPU v6e Blueprint:
   A new gke-tpu-v6-gcs.yaml blueprint has been added.
   This production-ready example demonstrates best practices for TPU workloads, including dedicated service accounts (Workload Identity) and performance-tuned GCS FUSE mounts for training data and checkpoints, all provisioned automatically.

NOTE: There was a change in output name made as a part of PR #4607 . Refer CP. This resulted in name mismatch of node_count variable in gke-job-template module. To solve the issue, we needed to pass the node_count variable explicitly from the blueprint itself.

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[SwarnaBharathiMantena]

LGTM

[shubpal07]

Checks passed. Failing tests were not linked to this PR

[SwarnaBharathiMantena]

LGTM