This PR makes it so long diagnostic messages no longer overflow the
status bar and push the right tools off-screen.

Here is an example with a long (placeholder) diagnostic message:

<img width="1136" alt="Screenshot 2024-01-18 at 9 47 07 PM"
src="https://github.com/zed-industries/zed/assets/1486634/18568527-c608-4d4a-9118-b84c6d81c13e">

Release Notes:

- Fixed long diagnostic messages overflowing the status bar.