CHARON_BEACON_NODE_ENDPOINTS doesn't support url params

🐞 Bug Report

Description

Currently using google cloud managed blockchain to host my BN/EN, and the provided endpoint needs a API key to be appended at the end of the url. For example: https://beacon.someid.blockchainnodeengine.com/?key=SOME_KEY

I've configured .env as CHARON_BEACON_NODE_ENDPOINTS=https://beacon.someid.blockchainnodeengine.com/?key=SOME_KEY

And it seems that its unable to query the BN api endpoints.

Has this worked before in a previous version?

NA

🔬 Minimal Reproduction

Set .env as CHARON_BEACON_NODE_ENDPOINTS=https://beacon.someid.blockchainnodeengine.com/?key=SOME_KEY

🔥 Error

Emit scheduled slot event: beacon api validators: nok http response {"slot": 2306413, "label": "validators", "status_code": 400, "endpoint": "/eth/v1/beacon/states/head/validators", "method": "GET", "data": "{\"error\":{\"code\":500,\"message\":\"BAD_REQUEST: unknown field `key`, expected `id` or `status`\",\"stacktraces\":[],\"status\":\"\"}}"}

WARN tracker    Failed to check inclusion: beacon api block_attestations: request block attestations failed {"slot": 2306408, "label": "block_attestations", "status": 400, "body": "{\"error\":{\"code\":400,\"message\":\"API key not valid. Please pass a valid API key.\",\"status\":\"INVALID_ARGUMENT\",\"details\":[{\"@type\":\"type.googleapis.com/google.rpc.ErrorInfo\",\"reason\":\"API_KEY_INVALID\",\"domain\":\"googleapis.com\",\"metadata\":{\"service\":\"blockchainnodeengine.googleapis.com\"}}]}}"}

🌍 Your Environment

Operating System:

Ubuntu 22

What version of Charon are you running? (Which release)

1.0.1

Anything else relevant (validator index / public key)?

Start at the handling of CHARON_BEACON_NODE_ENDPOINTS and follow how beacon API paths are joined to configured endpoints. Verify with the provided Google Cloud URL that its key remains query data for every request, while existing endpoint behavior still works; add regression coverage if the project has a relevant test.