Datepicker year range manual selection

[vaqxai]

Is your feature request related to a problem? Please describe.
I can't select years less than 5 before current year, this is bad for example when I want to specify a birthdate.

Describe the solution you'd like
I'd like to be able to manually define the year range for the year picker. There is already a scrollbar. There should be no such restriction. At least change the hardcoding to allow 100 years into the past.

Describe alternatives you've considered
No good alternative datepickers for egui