Fixed passing wrong offset value for comparing few DateComparisonType

[iranjith4]

When comparing yesterday's date with .compare(.isTomorrow), the function is returning true which is wrong.

Example:

let date = Date()
let tomorrow = date.offset(.day, value: 1)!
let yesterday = date.offset(.day, value: -1)!

//In version 5.0.1, these comparison returns `true`, which is a bug. 

if tomorrow.compare(.isYesterday) { 
    print(".isYesterday COMPARISION WRONG")
}

if yesterday.compare(.isTomorrow) {
    print(".isTomorrow COMPARISION WRONG")
}

The same happens for comparing the following DateComparisonType

isYesterday, isTomorrow, isLastWeek, isNextWeek, isLastMonth, isNextMonth, isLastYear, isNextYear 

Changes:

Bug:
During the comparison of the date, the offset for .isSameDay was passed based on the difference between Date() and self, which is a bug.

Fix:
Fixed it by passing the offset value calculated based on the DateComparisonType.