Implement String Interpolation Extensions to prevent users from using the long formatter syntax

[Blackjacx]

Expected behaviour

The is a super user friendly way to format dates into strings. We need one extension for each Date format (or one with 2 parameters, date and format):

extension String.StringInterpolation {
    mutating func appendInterpolation(date: Date, format: SHDateFormat) {
       let string = SHDateFormatter.shared.string(from: date, format: format)
       appendLiteral(string)
    }
}
// "Your time is \(date: Date(), format: .shortTimeNoDate)" <-- automatically compatible to new formats

OR

extension String.StringInterpolation {
    mutating func appendInterpolation(shortTimeNoDate date: Date) {
       let string = SHDateFormatter.shared.string(from: date, format: .shortTimeNoDate)
       appendLiteral(string)
    }
}
// "Your time is \(shortTimeNoDate: Date())" <-- a bit shorter but needs a new extension for each new format

[...]

Actual behaviour

Right now, to formt a string, a user has to use:

let time = SHDateFormatter.shared.string(from: Date(), format: .shortTimeNoDate)
let string = "Now is \(time)"