fix: find the caret domrect with largest bottom value

[dominictb]

Details

Related Issues

$ https://github.com/Expensify/App/issues/46389 PROPOSAL: https://github.com/Expensify/App/issues/46389#issuecomment-2255658889

Manual Tests

1. Add overflow and maxHeight attribute in: https://github.com/Expensify/react-native-live-markdown/blob/main/example/src/App.tsx#L190-L196
2. Run example web app
3. Insert multiple-line text until a scroll bar is shown on the right
4. On a new line insert a markdown text (eg. bold)
5. Hit the enter key on the keyboard

Verify that: the text input should scroll automatically down to reveal the new line.

Linked PRs