#### Is your feature request related to a problem? Please describe.
No.

#### Describe the solution you'd like
#4734 Changed the entire behavior of the params serializer, breaking using any custom functionality on the consumer side. Add a boolean switch to mimic pre 1.x behavior (default is false) and send the params directly to the encode function

#### Describe alternatives you've considered
Tried working with new solution; it did not pan out well and led to more bugs with our requests

lib/helpers/buildURL.js
'use strict';
import utils from '../utils.js';
import AxiosURLSearchParams from '../helpers/AxiosURLSearchParams.js';
/**
 * It replaces all instances of the characters `:`, `$`, `,`, `+`, `[`, and `]` with their
 * URI encoded counterparts
 *
 * @param {string} val The value to be encoded.
 *
 * @returns {string} The encoded value.
 */
function encode(val) {
  return encodeURIComponent(val).
    replace(/%3A/gi, ':').
    replace(/%24/g, '$').
    replace(/%2C/gi, ',').
    replace(/%20/g, '+').
    replace(/%5B/gi, '[').
    replace(/%5D/gi, ']');
}
/**
 * Build a URL by appending params to the end
 *
 * @param {string} url The base of the url (e.g., http://www.google.com)
 * @param {object} [params] The params to be appended
 * @param {?object} options
 *
 * @returns {string} The formatted url
 */
export default function buildURL(url, params, options) {