0.4.28: A few fast-avro fixes

What's Changed

• Support custom logical types derived from fixed types by @chadparry in #565
• Fix nested map and array problems by @pamitm in #576
• Fix the map/array for nested maps/array with unions at play by @pamitm in #578
• Handle Nullable Unions Of Enums Correctly by @pamitm in #575
• Seek Field Action Correctly When Writer Is Required And Reader Is Nullable by @pamitm in #573
• Support java keywords as class names for records during generic decode by @pamitm in #577

New Contributors

• @chadparry made their first contribution in #565
• @pamitm made their first contribution in #576

Full Changelog: 0.4.25...0.4.28