Stabilize Cardano DB v2 client CLI/library - Phase 4

[jpraynaud]

Why

We want to deprecate the Cardano DB v1 backend certification as a final step before its sunset.

What

Deprecate the v1 backend in the cardano-db command and in the library.

How

• Update the dev blog post:
  • Plan for update of the blog post with next distribution (@jpraynaud)
• Deprecate the v1 backend in the client library
• Deprecate the v1 backend in the client CLI:
  • Display a deprecation warning
• Tests:
  • Aggregator stress test if necessary
  • Check all manual CI workflows
    • Mithril Client multi-platform test
  • E2e test
• Update documentation:
  • Mithril client node commands