oasis-node/status: Correctly show light client status

What

oasis-node control status should display the local light client status.

This client is created for the:

1. stateless client node - see
2. full node's state sync see

Motivation

This would be useful to monitor stateless client (e.g. was missing this during #6385), or possibly consensus state sync.

Existing status

Current light client status is confusing / incorrect:

  "light_client": {
    "latest_height": 0,
    "latest_hash": "0000000000000000000000000000000000000000000000000000000000000000",
    "latest_time": "0001-01-01T00:00:00Z",
    "oldest_height": 0,
    "oldest_hash": "0000000000000000000000000000000000000000000000000000000000000000",
    "oldest_time": "0001-01-01T00:00:00Z",
    "peer_ids": [
      "12D3KooWHjqvFidQgDcw24A88KX1oaPjvqiLq6X8nPi4zMnSCDu6",
      "12D3KooWKTvsowgyv3WRTVm2dvEBtxpKsshWKtKJmGriGDPdzRBM"
    ]
  },

Concretely this is not even light client, but an actual wrapper over the remote providers.

Moreover, the linked documentation is a bit misleading as trusted blocks are not obtained from the local consensus backend?

Solution:

Two statuses:

1. One for the the actual local light client (if applicable depending on the mode/config).
2. One for the consensus light service (consensusAPI.LightService), where we should probably get rid of anything but the remote providers peer ids.
   • Albeit I am confused why not use full node consensus backend here over remote providers?

Any preference for nesting and naming?

Btw where is the light client serve part? I don't see any like for other protocols so I assume CometBFT full nodes serve this by default?

Start with oasis-node control status and the linked Go entry points in consensus/cometbft/light/client.go, consensus/cometbft/cometbft.go, full/full.go, and light/service.go. Trace which status currently wraps remote providers, then separate the local light-client status from consensus LightService data. Done means both statuses accurately reflect their respective components and naming or nesting is settled.