https://smartcontract-it.atlassian.net/browse/OPDATA-3674

Description

We need total balance for a list of Avalanche addresses for a proof-of-reserves feed.
Some of these addresses are P-chain addresses.
The avalanche-platform EA already interacts with Avalanche P-chain, although it currently doesn't appear to be used by anything.

Unfortunately its existing balance endpoint only returns the stake of the requested addresses.

This PR adds a new totalBalance endpoint which returns the sum of locked and unlocked balances and stake.

Balances are for a specific asset, which defaults to the asset ID of the native AVA token, but can be set to something else as well.

Changes

1. Add new endpoint and transport for totalBalance.
2. Make 2 requests per address for balances and stake.
3. Use grouped runner to limit simultaneous requests.

Steps to Test

1. Unit tests and integration tests added.
2. Tested manually with proof-of-reserves in another branch with other necessary changes in por-address-list.

curl --silent -S -X POST "$PROOF_OF_RESERVES_ADAPTER_URL" -H 'Content-Type: application/json' -d '{
  "data": {
  "endpoint": "multiReserves",
  "input": [
    {
      "protocol": "por_address_list",
      "protocolEndpoint": "virtune",
      "pattern": "^(?!P-)",
      "accountId": "VIRAVAX",
      "network": "avalanche",
      "chainId": "43114",
      "indexer": "eth_balance"
    },
    {
      "protocol": "por_address_list",
      "protocolEndpoint": "virtune",
      "pattern": "^P-",
      "accountId": "VIRAVAX",
      "network": "avalanche",
      "chainId": "43114",
      "indexer": "avalanche_platform",
      "indexerEndpoint": "totalBalance"
    }
  ]
}
}'
{
  "jobRunID": "1",
  "result": "141310543515847143410000",
  "statusCode": 200,
  "data": {
    "result": "141310543515847143410000",
    "details": "{\"result\":\"55629103628758143410000\"},{\"result\":\"85681439887089000000000\"}",
    "statusCode": 200,
    "decimals": 18,
    "timestamps": {
      "providerDataRequestedUnixMs": 1758299425125,
      "providerDataReceivedUnixMs": 1758299427398
    }
  },
  "meta": {
    "adapterName": "PROOF_OF_RESERVES"
  },
  "metricsMeta": {
    "feedId": "63d2efe3aa16b75a6e1e35401f74056e"
  }
}

Quality Assurance

• If a new adapter was made, or an existing one was modified so that its environment variables have changed, update the relevant infra-k8s configuration file.
• If a new adapter was made, or an existing one was modified so that its environment variables have changed, update the relevant adapter-secrets configuration file or update the soak testing blacklist.
• If a new adapter was made, or a new endpoint was added, update the test-payload.json file with relevant requests.
• The branch naming follows git flow (feature/x, chore/x, release/x, hotfix/x, fix/x) or is created from Jira.
• This is related to a maximum of one Jira story or GitHub issue.
• Types are safe (avoid TypeScript/TSLint features like any and disable, instead use more specific types).
• All code changes have 100% unit and integration test coverage. If testing is not applicable or too difficult to justify doing, the reasoning should be documented explicitly in the PR.