#API change

I found that #16 does work, but due to the limitations of patches you cannot apply changes to composer.json to say install/update another modules requirements - https://docs.cweagans.net/composer-patches/troubleshooting/non-patchable...

I have made some changes to #16 to allow the fields to be empty and should not cause any issues.

Steps to apply:

1. Install hubspot module 3.x: composer require 'drupal/hubspot:3.x-dev@dev'
2. Alter composer.lock hubspot-php requirement:
   From:
   

   "require": {
                   "drupal/core": "^8.9 || ^9 || ^10",
                   "drupal/webform": "*",
                   "hubspot/hubspot-php": "^3.0"
               },

   To:

   "require": {
                   "drupal/core": "^8.9 || ^9 || ^10",
                   "drupal/webform": "*",
                   "hubspot/hubspot-php": "^5.2"
               },

3. Install hubspot-php 5.2: composer require hubspot/hubspot-php:^5.2 -W
4. Apply patch #16/#22