setCustomEmojiStickerSetThumbnail
suspend fun TelegramBot.setCustomEmojiStickerSetThumbnail(stickerSetName: StickerSetName, customEmojiId: CustomEmojiId): Boolean
suspend fun TelegramBot.setCustomEmojiStickerSetThumbnail(stickerSet: StickerSet, customEmojiId: CustomEmojiId): Boolean