Feat: support GCP KMS ancillary signature in infrastructure

[jpraynaud]

Content

This PR includes the support for GCP KMS ancillary signature in infrastructure:

• Terraform scripts have been modified to support custom ancillary signature
• Terraform deployments have been modified in the CI to support custom ancillary signature
• Ancillary verification keys have been created in the infrastructure
• Network configurations have been updated in the documentation website

Pre-submit checklist

• Branch
  • Crates versions are updated (if relevant)
  • CHANGELOG file is updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • All check jobs of the CI have succeeded
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested

Issue(s)

Relates to #2362

[github-actions]

Test Results

    3 files  ±0     57 suites  ±0   11m 52s ⏱️ +16s
1 875 tests ±0  1 875 ✅ ±0  0 💤 ±0  0 ❌ ±0 
2 337 runs  ±0  2 337 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 8a9abc8. ± Comparison against base commit e7358f2.

♻️ This comment has been updated with latest results.