currently when you click the emoji picker button there is only an emoji picker, the picker should have two tabs, emoji and stickers, if user select the stickers tabs then the saved stickers should be shown for selection

user add a sticker to the picker by selecting an sticker message in a chat and using a "save sticker" option in the menu then it will be available in the picker (internally it is saved in a "stickers" folder in the app's internal storage)