core-datepicker: Step by year with disabled dates does not always work

[skjalgepalg]

Relates to #386 and #319

If entirety of December 2023 is disabled, but jan-nov 2023 is available, a core-datepicker set to any day in December 2022 will deem the year 2023 as disabled. But if it is set to any day in jan-nov 2022, the year 2023 is not disabled

Should we handle this in the same way as we do months?

• if target day in year is disabled, look for first available day in target month
  • if that fails, look for first available day in target year.

Do we have any use-cases to help us shape a solution for a good user experience?