Add support for iOS 15 and unicode release v13 (#1)

Sources/EmojiSourceKit/StringHelper.swift

@@ -0,0 +1,33 @@
+//
+//  StringHelper.swift
+//  
+//
+//  Created by Niklas Amslgruber on 10.06.23.
+//
+
+import Foundation
+
+extension String {
+
+    func trim() -> String {
+        return self.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    func asEmoji() -> String? {
+        guard let unicodeNumber = Int(self, radix: 16), let unicode = Unicode.Scalar(unicodeNumber) else {
+            return nil
+        }
+        return String(unicode)
+    }
+}
+
+extension String.SubSequence {
+
+    func trim() -> String {
+        return String(self).trim()
+    }
+
+    func asEmoji() -> String? {
+        return String(self).asEmoji()
+    }
+}