emoji picker improvements (#2392)

* rework emoji picker

* dynamic position

* always prefer the left if it will fit

* add accessibility label

* Update EmojiPicker.web.tsx

oops. remove accessibility from fake button

src/view/com/composer/text-input/TextInput.tsx

@@ -32,6 +32,7 @@ import {POST_IMG_MAX} from 'lib/constants'
 export interface TextInputRef {
   focus: () => void
   blur: () => void
+  getCursorPosition: () => DOMRect | undefined
 }
 
 interface TextInputProps extends ComponentProps<typeof RNTextInput> {
@@ -74,6 +75,7 @@ export const TextInput = forwardRef(function TextInputImpl(
     blur: () => {
       textInput.current?.blur()
     },
+    getCursorPosition: () => undefined, // Not implemented on native
   }))
 
   const onChangeText = useCallback(