feat: add data_disk_volume_ids output

What does this MR do?

Adds a new output to the gitlab_aws_instance module: data_disk_volume_ids.

This contains an array of AWS Volume Identifiers for the Data Disks attached to an instance.

This could prove very helpful during a recovery operation. See https://gitlab.com/gitlab-com/gl-infra/gitlab-dedicated/team/-/merge_requests/161/diffs#8a97b12f9cb4116f1c7622accaf5891a982c198d_0_62 for an example situation.

Downstream MR: https://gitlab.com/gitlab-com/gl-infra/gitlab-dedicated/instrumentor/-/merge_requests/498

Related issues

Author's checklist

When ready for review, the Author applies the workflowready for review label and mention @gl-quality/get-maintainers:

• Merge request:
  • Corresponding Issue raised and reviewed by the GET maintainers team.
  • Merge Request Title and Description are up to date, accurate, and descriptive
  • MR targeting the appropriate branch
  • MR has a green pipeline
  • MR has no new security alerts in the widget from the Secret Detection and IaC Scan (SAST) jobs.
• Code:
  • Check the area changed works as expected. Consider testing it in different environment sizes (1k,3k,10k,etc.).
  • Documentation created/updated in the same MR.
  • If this MR adds an optional configuration - check that all permutations continue to work.
  • For Terraform changes: setup a previous version environment, then run a terraform plan with your new changes and ensure nothing will be destroyed. If anything will be destroyed and this can't be avoided please add a comment to the current MR.
• Create any follow-up issue(s) to support the new feature across other supported cloud providers or advanced configurations. Create 1 issue for each provider/configuration. Contact the Quality Enablement team if unsure.