Element web hides unread count with bell image on hover

### Description

When I consider reading a room my hands move the cursor over the name so the unread count gets hidden. Then I'm no longer sure I'm pointing at the right room.

### Steps to reproduce

- Look at room list.
- Consider reading a room with an unread count.
- Point to the room.
- The unread count vanishes, causing me to wonder if I'm pointing at the room I intended.
- Move the cursor off the room to check the count, then back on to select.

When I point at something the information content should stay the same or increase, not decrease. When pointing at a room I should still see the unread count.

Logs being sent: no

### Version information

- **Platform**: web, chat.mozilla.org

For the web app:

- **Browser**: Firefox 78 and 80.
- **OS**: Ubuntu
- **URL**: https://chat.mozilla.org/

Reproduce the issue in the web room list using Firefox on Ubuntu, as described, and inspect the hover behavior for rooms with unread counts. The change is complete when hovering a room no longer hides its unread count and the room remains identifiable before selection. No source file or test is named, so locate the room-list UI entry point and its existing hover tests first.

Written by the indexing model from the issue text.