Gravity Forms 2.8.9

- Added cosmetic tweaks to the form editor.
- Updated design of progress bar, added new design options.
- Differentiated secondary buttons from primary buttons and improved styling for secondary buttons.
- Updated toggle animations on settings pages.
- Updated database column widths to be compatible with MySQL 8.0.17+.

- Updated the translated countries list to be sorted alphabetically.
- API: Added GF_Field_Address::get_default_countries() which returns the default array of countries using the ISO 3166-1 alpha-2 code as the key to the country name.
- API: Fixed the value not being padded when true is passed for the fifth argument of the Currency.numberFormat method in gravityforms.js.
- API: Fixed an issue where GF_Field_Address::get_country_code() would return null for some translated countries.

- Fixed an issue with the empty form validation ignoring the values of fields with visibility set to hidden.