feat(cloudformation): provision AWS::Batch::* resources + tfacc

[vieiralucas]

Final batch of the AWS Batch service: CloudFormation provisioning + terraform-provider-aws acceptance coverage.

What

• CFN provisioner for AWS::Batch::ComputeEnvironment, AWS::Batch::JobQueue, AWS::Batch::JobDefinition. Resources are written into the Batch control plane on stack create and removed on stack delete.
• Restart-safe: registers a cfn_snapshot_hooks entry for batch, so CFN-provisioned resources survive a restart in persistent mode (the CloudFormation-provisioned resources are not persisted and vanish on restart (persistent mode) #1766 write-through lesson). Delete matches the stored record by its *Arn field so hyphenated names round-trip cleanly.
• tfacc: new batch service + shard running TestAccBatch(ComputeEnvironment|JobQueue|JobDefinition)_basic, with AWS_ENDPOINT_URL_BATCH routing.
• Tests: CFN e2e (stack creates CE/JQ/JD, delete removes them) + a restart-persistence e2e. Both green locally.
• Docs page updated.

Verification

• cargo build --bin fakecloud clean
• cargo clippy -p fakecloud-cloudformation -p fakecloud-tfacc clean
• e2e cfn_provisions_batch_resources + cfn_provisioned_batch_survives_restart pass

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Summary by cubic

Adds CloudFormation support for AWS::Batch::ComputeEnvironment, AWS::Batch::JobQueue, and AWS::Batch::JobDefinition. Stacks create real Batch control-plane records that persist across restarts and are cleaned up on delete; TF acc tests now pass cleanly.

• New Features

  • CFN provisioner writes to Batch state and registers a cfn_snapshot_hooks entry for batch (restart-safe).
  • Delete matches resources by *Arn so hyphenated names round-trip cleanly.
  • tfacc: new batch service/shard running TestAccBatch(ComputeEnvironment|JobQueue|JobDefinition)_basic with AWS_ENDPOINT_URL_BATCH.
  • E2E coverage for CFN create/delete and restart persistence; docs updated.

• Bug Fixes

  • Compute environments now return ecsClusterArn on describe.
  • Job definitions default optional containerProperties lists (environment, mountPoints, resourceRequirements, secrets, ulimits, volumes) to empty arrays.

^{Written for commit ebc8dbf. Summary will update on new commits.}