better performance in stickerbroswer

Emoji.sticker can return nil
added tests to measure .sticker perfomance
delete redundant stickerbrowserviewcontroller

StickerSlackTests/StickerSlackTests.swift

@@ -0,0 +1,20 @@
+//
+//  StickerSlackTests.swift
+//  StickerSlackTests
+//
+//  Created by neon443 on 29/10/2025.
+//
+
+import Testing
+
+struct StickerSlackTests {
+	var hoarder = EmojiHoarder()
+	
+	@Test func example() async throws {
+		// Write your test here and use APIs like `#expect(...)` to check expected conditions.
+		for emoji in hoarder.emojis {
+			print(emoji.sticker)
+		}
+	}
+	
+}