create an rpc endpoint for the 4 datapoints requested in /lib/pool-interface.js collectMiningParameters

[snissn]

in /lib/pool-interface.js collectMiningParameters

we make the following 4 rpc requests in serial. we should run the commands to hit a different endpoint that servers all 4 values

async collectMiningParameters(minerEthAddress, previousMiningParameters) {
// create a client
var rpcClient = this.jsonrpcClient;
var args = []
var poolEthAddress = await new Promise(function (fulfilled, rejected) {
rpcClient.request('getPoolEthAddress', args, function (err, response) {
if (err) { rejected(err); return; }
if (typeof response == 'undefined') { rejected(response); return; }

            fulfilled(response.result)
        });
    });

    var poolChallengeNumber = await new Promise(function (fulfilled, rejected) {
        rpcClient.request('getChallengeNumber', args, function (err, response) {
            if (err) { rejected(err); return; }
            if (typeof response == 'undefined') { rejected(response); return; }
            fulfilled(response.result)
        });
    });

    var poolMinimumShareDifficulty = await new Promise(function (fulfilled, rejected) {
        rpcClient.request('getMinimumShareDifficulty', [minerEthAddress], function (err, response) {
            if (err) { rejected(err); return; }
            if (typeof response == 'undefined') { rejected(response); return; }
            fulfilled(response.result)
        });
    });

    var poolMinimumShareTarget = await new Promise(function (fulfilled, rejected) {
        rpcClient.request('getMinimumShareTarget', [minerEthAddress], function (err, response) {
            if (err) { rejected(err); return; }
            if (typeof response == 'undefined') { rejected(response); return; }
            fulfilled(response.result)
        });
    });