Agnostic baker benefits from generic watchdog

Parent MR: !16426 (merged)

This MR aims to benefit from the introduction of the Lwt_process_watchdog introduced by !15485 (merged) to bring more resilience to the baker processes.

Because of this integration, it requires a quite important refactoring.

This MR is on top of !15485 (merged)

Manually testing the MR

Compile the uncompiled-by-default agnostic baker binary with something like rm -rf octez-agnostic-baker && dune build src/bin_agnostic_baker/main_agnostic_baker.exe && mv _build/default/src/bin_agnostic_baker/main_agnostic_baker.exe octez-agnostic-baker

Run a sandbox scenario with the agnostic baker that is actively baking. Kill the baker process (not the agnostic one) and enjoy the automatic restart.

Scenario:

• Start a sandboxed node:

  ./src/bin_node/octez-sandboxed-node.sh 1 --connections 0

• Start the agnostic baker on this node:

  ./octez-agnostic-baker --base-dir <client_dir> -- --endpoint http://localhost:18731 run with local node <node_dir> --liquidity-baking-toggle-vote pass --without-dal

• Kill the baker process:
  • Find the process pid (appears when starting the baker or with the following command)

    ps aux | grep 'octez-baker-alpha'

  • Kill it
• Enjoy

  Shutting down the baker...
  Error:
    Lwt.Resolution_loop.Canceled
  Jan 28 11:05:58.761: baker ProtoALphaAL (pid 55882) terminated abnormally with exit code 127
  Jan 28 11:05:58.762: baker ProtoALphaAL was started on pid 57105
  Jan 28 11:05:59.002: read liquidity baking toggle vote = pass
  Jan 28 11:05:59.003: read adaptive issuance vote = pass

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR