feat: custom calendar support (#7803)
* Add createCalendar prop to Calendar/RangeCalendar
* Update date math for adding/subtracting months
* Add doc comments
* Simplify isEqualDay/Month/Year
* Display the calendar month name based on the result of getCurrentMonth()
* Format aria labels based on current month
* Refactor to return weeksInMonth from useCalendarGrid hook
* Fix month's year display in calendar header for custom calendars
* Update Calendar and RangeCalendar docs to talk about custom calendars
* Add custom calendar stories to Calendar and RangeCalendar
* Fix range selection styles for custom calendar
* Write tests for custom calendar date math
* Write tests for changes to queries.ts
* Use customCalendarImpl in stories
* Write tests for visible range description with custom calendar
* Update calendar docs to use jsx syntax
* Update calendar docs to fully implement Calendar interface to satisfy the type checker
* Update calendar docs
Finally learned how to run `make check-examples` myself
* wip
* fix
* feat: use suggestion from @devongovett to implement custom cal w/ julian dates
* chore: remove unnecessary code in queries & manipulation
* feat: zero-index the week pattern in 454 calendar impl
* chore: remove unused code in utils
* test: update useCalendar tests for custom calendar
* test: verify conversion for end of big year
* feat: update createCalendar prop types
* feat: add createCalendar prop to DatePicker and DateRangePicker
* Update docs
* update examples
* ts
* docs: update docs for DatePicker and DateRangePicker
* docs: remove custom calendar system section in useCalendar hooks
* chore: more code cleanup
* fix: mdx example
* Add isEqualCalendar function
* Update docs
---------
Co-authored-by: Devon Govett <devongovett@gmail.com>
