Как сортировать и соединять по ключам в Javascript

const data = {
  amount_2       : "1000",
  amount_3       : "1200",
  date_2         : "15/2/2019",
  date_3         : "15/3/2019",
  modeOfPayment_2: "Cash",
  modeOfPayment_3: "Cash",
  note_2         : "áßðáßðáßð↵áß",
  note_3         : "",
  refNum_2       : "11111",
  refNum_3       : "Fffff",
  submittedByID_2: "T62tgJcjieSJsAEJT69VfpRc5Mw2",
  submittedByID_3: "T62tgJcjieSJ"
};

const result = Object.values(Object.entries(data).reduce((dict, [key, val]) => {
  // reduce is called for each key/value pair in your input data
  // here we add the key/value pair in the proper entry based
  // on the number extracted at the end
  const num = key.match(/(\d+)$/); // get number at end of key
  const newKey = key.replace(/_(?=\d)/, ''); // remove underscore before digit
  dict[num] = dict[num] || {}; // create a default entry if needed
  dict[num][newKey] = val; // set value for the new key
  return dict; // return intermediate dictionary
}, {}));

console.info(result);

let result = {
  amount_2       : "1000",
  amount_3       : "1200",
  date_2         : "15/2/2019",
  date_3         : "15/3/2019",
  modeOfPayment_2: "Cash",
  modeOfPayment_3: "Cash",
  note_2         : "áßðáßðáßð↵áß",
  note_3         : "",
  refNum_2       : "11111",
  refNum_3       : "Fffff",
  submittedByID_2: "T62tgJcjieSJsAEJT69VfpRc5Mw2",
  submittedByID_3: "T62tgJcjieSJ"
};

/* Compose Object.values() and Object.entries() with reduce. Here we get
the key/value pairs (entries) of the input "results" object, and reduce
the key/values into an object of nsted objects of key/values grouped by 
number.
We then aquire an array of the grouped objects using Object.values() */
const groupedResult = Object.values(Object.entries(result).reduce((output, [key,value]) => {
   
  /* Extract key and number parts of current entry of result object */
  const [, name, number] =  key.match(/^(.*)_(\d+)$/);
  
  /* Fetch or insert (empty) object for the number corresponding to
  this entries key */
  const group = output[ number ] = output[ number ] || {}
  
  /* Compose a key with number suffix and insert value into group
  object for composed key */
  group[ `${name}${ number }` ] = value;
  
  /* Return current output object for next iteration of reduce */
  return output;

}, {}))

console.info(groupedResult);

const { flow, toPairs, groupBy, partialRight: pr, map, fromPairs, mapKeys } = _;

const pattern = /_+(\d+)$/;
const getKeyId = ([k]) => (k.match(pattern) || [''])[0];

const fn = flow(
  toPairs, // convert to entries
  pr(groupBy, getKeyId), // group by the number in the key
  pr(map, flow( // map back to object
    fromPairs, // combine the entries in the group
    pr(mapKeys, (v, k) => k.replace(pattern, '$1')) // update the keys
  ))
);

const data = {
  amount_2       : "1000",
  amount_3       : "1200",
  date_2         : "15/2/2019",
  date_3         : "15/3/2019",
  modeOfPayment_2: "Cash",
  modeOfPayment_3: "Cash",
  note_2         : "áßðáßðáßð↵áß",
  note_3         : "",
  refNum_2       : "11111",
  refNum_3       : "Fffff",
  submittedByID_2: "T62tgJcjieSJsAEJT69VfpRc5Mw2",
  submittedByID_3: "T62tgJcjieSJ"
};

const result = fn(data);

console.info(result);

<script src = "https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

const { flow, toPairs, groupBy, map, fromPairs, mapKeys, replace } = _;

const pattern = /_+(\d+)$/;
const getKeyId = ([k]) => (k.match(pattern) || [''])[0];

const fn = flow(
  toPairs, // convert to entries
  groupBy(getKeyId), // group by the number in the key
  map(flow( // map back to object
    fromPairs, // combine the entries in the group
    mapKeys(replace(pattern, '$1')) // update the keys
  ))
);

const data = {
  amount_2       : "1000",
  amount_3       : "1200",
  date_2         : "15/2/2019",
  date_3         : "15/3/2019",
  modeOfPayment_2: "Cash",
  modeOfPayment_3: "Cash",
  note_2         : "áßðáßðáßð↵áß",
  note_3         : "",
  refNum_2       : "11111",
  refNum_3       : "Fffff",
  submittedByID_2: "T62tgJcjieSJsAEJT69VfpRc5Mw2",
  submittedByID_3: "T62tgJcjieSJ"
};

const result = fn(data);

console.info(result);

<script src='https://cdn.jsdelivr.net/g/lodash@4(lodash.min.js+lodash.fp.min.js)'></script>