Stop using @dappnode/types & Use Stakers Network in `stakers-metrics`

[Marketen]

Old stakers-metrics service of dappnode exporter uses @dappnode/types in order to get the JSON RPC api of staking clients, given a DNP name: https://github.com/dappnode/DAppNodePackage-exporter/blob/73f2e6d6ae4d6c9d037617a8a9916cae0fb83c70/stakers-metrics/src/utils.ts#L18C23-L18C47

The method getJsonRpcApiFromDnpName is not exporter anymore in @dappnode/types > 0.1.31. Now that we have stakers network, getting JSON RPC api of the current staker clients should be easier