Gravity Forms HubSpot Add-On v1.8.3

- Fixed an issue that causes the API to initialize on all front-end pages containing forms and all admin pages.
- Fixed an issue where multiple auth token refresh requests can occur around the same time.
- Fixed an issue where HubSpot forms are recreated when reconnecting to the same HubSpot account.

- Added support for async (background) feed processing to improve form submission performance.

- Fixed an issue with lifecycle stages which causes feeds to error when being saved or updated.
- Fixed a typo in the "clear cache" setting description.