remove basic auth stripping from the VC

[rolfyone]

The VC should be able to access beacon-nodes that use basic auth.

We should still make sure that doesn't leak into logs, but it'd be helpful for some customers if we remove the authentication stripping from the URL to make this possible.

ref.

https://github.com/Consensys/teku/blob/master/validator/remote/src/main/java/tech/pegasys/teku/validator/remote/RemoteBeaconNodeEndpoints.java#L28