Enhance terraform infrastructure

[jpraynaud]

Content

This PR includes enhancements to the terraform deployment of the Mithril infrastructure:

• Separate data disk from VM system disk
• Setup data disk snapshots
• Clone cardano configurations files in the assets directory of the repository and use them
• Create a mithril.network.tf recipe that handles network creation in Docker and on which other components depend
• Make docker logs configurable (json-file or gcplogs)
• Add an authentication mechanism to possibly keep aggregator private

Pre-submit checklist

• Branch
  • Crates versions are updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • No clippy warnings in the CI
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested

Issue(s)

Closes #930

[github-actions]

Test Results

3 files  ±    0  0 suites   - 30   0s ⏱️ - 5m 41s
0 tests  - 574  0 ✔️  - 574  0 💤 ±0  0 ❌ ±0 
0 runs   - 606  0 ✔️  - 606  0 💤 ±0  0 ❌ ±0 

Results for commit b2d9441. ± Comparison against base commit 27d5783.