Validator Client in REST mode should not drop URL query strings #14528
Description
💎 Issue
Background
a user wasn't able to include GCP API_KEYS in the URL due to
- prysm dropping the query strings from URLs https://github.com/prysmaticlabs/prysm/blob/develop/api/client/client.go#L64
- prysm not allowing custom headers for validator client API calls
Solution
Ideally we either allow for query strings or maybe allow custom headers for API calls?