Changes made to:
- PlainDate
- PlainYearMonth
- ZonedDateTime
- PlainDateTime
- PlainMonthDay
Merged calendar-number.js and calendar-wrong-type.js, due to no special behaviour of number to be tested.
Extracted string tests to calendar-iso-string.js and renamed the file to calendar-invalid-iso-string.js, due to the contents of the file initially testing invalid ISO strings.
Closes#3873