Default the first day of the week to Monday everywhere

[GregoryTravis]

We have different defaults in different places -- Sunday is the Excel default, but Monday is the ISO default.

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Time/Date_Period.enso:    Week (first_day:Day_Of_Week = Day_Of_Week.Monday)
distribution/lib/Standard/Base/0.0.0-dev/src/Data/Time/Day_Of_Week.enso:    to_integer self first_day=Day_Of_Week.Sunday start_at_zero=False =
distribution/lib/Standard/Base/0.0.0-dev/src/Data/Time/Day_Of_Week.enso:Day_Of_Week.from (that : Integer) (first_day:Day_Of_Week=Day_Of_Week.Sunday) (start_at_zero:Boolean=False) =
distribution/lib/Standard/Table/0.0.0-dev/src/Refined_Types/Date_Column.enso:    first_of_week self (first_day:Day_Of_Week=Day_Of_Week.Monday) -> Column & Date_Column =
distribution/lib/Standard/Base/0.0.0-dev/src/Data/Time/Date.enso:                ordinal = self.day_of_week.to_integer first_day=Day_Of_Week.Sunday start_at_zero=False