Calendar: Changing the locale to one for which the week starts on Monday doesn't change the view

[simeonoff]

Description

Given a locale which specifies that the week starts on Monday, like Bulgarian for instance, doesn't modify the calendar view. The week still starts on Sunday. This behavior is different than the one we have in Angular.

Steps to reproduce

1. Open the calendar story
2. In the control panel, change the locale property to bg

Result

The week still starts on a Sunday

Expected result

The week should start on a Monday

[simeonoff]

After some research, it turns out that Angular has specific implementation for additional data based on locale, like what's the first day of the week.

Seems like there is a proposal for standard browser implementation of this feature. Once it lands in all major browsers, we can get back to this feature.