Improve chat room styling: add separator, increase emoji/attachment icon size, and keep send button always visible

### Your use case

**Description:**
I suggest the following UI improvements for better chat room styling similar to the attached screenshot.:

1. Add a separator between the chat room (message history area) and the message input/send section.
2. Increase emoji icon size for better visibility.
3. Increase attachment icon size for easier tapping.
4. Keep the send button always visible (not hidden)

These changes would improve the overall user experience and visual clarity.

Of course, you placed this image on the main page of the Element GitHub, and this image has all of these features **but the current version does not include them**: