When a constant doesn’t match it’s sanitised form, output the quoted constant

[tonyarnold]

This PR fixes the issue raised in #52.

This is useful when the storyboard file name on disk has spaces or other characters that are stripped by the string sanitiser.

Before the changes introduced in this PR:

public enum StoryboardNames: String {
    case ConstantsProperties
    case DebugLog // filename is actually "Debug Log.storyboard"
    case DocumentProperties   
}

After the changes introduced in this PR:

public enum StoryboardNames: String {
    case ConstantsProperties
    case DebugLog = "Debug Log"
    case DocumentProperties
}

[ashfurrow]

Shame this never got merged.