Make Calendar WCAG 2.1 compatible

[ExtAnimal]

Standard: https://www.w3.org/TR/WCAG21/

More practical info: https://help.time.ly/event-management/how-to-set-up-calendar-design-for-accessibility-compliance/

• [x] Add accessibility theme
• [x] Make day header cells visitable as role="columnheader"
• [x] Make day header cell's dayName visitable as role="link" as click links to DayView for that date
• [x] Make day cells visitable as role="gridell"
• [x] Make MonthView's week number visitable as role="link" as it links to the WeekView
• [x] Make YearView month and week number buttons role="link" as they link to month and week view.
• [x] Make YearView cells visible as role="button"

[rgallagherab]

Hi, I was checking back on an issue filled by my colleague in March about A11Y violations a large customer reported that need to be resolved, and I came across this recent issue.

I know that "Calendar" is a separate product from Scheduler Pro, but will this compliance effort also be applied to that tool?

[matsbryntse]

@rgallagherab The link you posted seems broken, can you please post it again and we'll take a look!

[rgallagherab]

Sorry @matsbryntse I've updated my original comment. I'm not sure what happened with that when I originally posted, but it should be good now.