Feat(infra): support follower aggregator in infra

[jpraynaud]

Content

This PR includes an update of the terraform infrastructure for Mithril networks:

• An optional leader aggregator
• An optional bootstrap peer for the P2P network
• Add Passthrough or P2P option for signer registration in the signer relay
• Add Passthrough or P2P option for signature registration in the signer relay
• Simplified the docker compose files with merging for signer and aggregator
• Adapt the aggregator infrastructure for follower aggregator
• Adapt the signer infrastructure for follower aggregator
• Adapt the CI workflows
• Add a new dev-follower-preview network

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
• Documentation
  • No new TODOs introduced

Issue(s)

Closes #2391

[github-actions]

Test Results

    3 files  ±0     57 suites  ±0   11m 38s ⏱️ -7s
1 831 tests ±0  1 831 ✅ ±0  0 💤 ±0  0 ❌ ±0 
2 245 runs  ±0  2 245 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 5b26a66. ± Comparison against base commit 985975d.

♻️ This comment has been updated with latest results.