feat: add da client can be initialized with the gcs seed

[JayT106]

What ❔

Implement DA client can init with a encrypted seed from google cloud storage. The encrypted seed has been encrypted by a HSM key stored in google KMS.

There are 3 environment variables need to be setup for enabling this feature.
DA_SECRETS_FROM_GCS="true"
DA_SECRETS_GCS_BUCKET_NAME=[gcs-bucket-name]
DA_SECRETS_KMS_DECRYPT_KEY_NAME=[google-kms-key-path]

Why ❔

Can use the seed encrypted by KMS key and storing in gcs and able to use it in DA client without exposing the key details in the deploy node.

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• Code has been formatted via zkstack dev fmt and zkstack dev lint.