In this PR:
- [x] Add support for dragging / copying image files into chat.
- [x] Don't remove image placeholders when submitting.
- [x] Add tests.
Works for:
- Image Files
- Dragging MacOS Screenshots (Terminal, iTerm)
Todos:
- [ ] In some terminals (VSCode, WIndows Powershell, and remote
SSH-ing), copy-pasting a file streams the escaped filepath as individual
key events rather than a single Paste event. We'll need to have a
function (in a separate PR) for detecting these paste events.