"Encryption can not be verified" icon should not look like "This conversation is encrypted" icon


### Description

Currently, the icon that marks a conversation/room as encrypted is exactly the same (maybe slightly scaled down) as the icon that shows for a single message that "the authenticity of this encrypted message can't be guaranteed on this device".

Ideally, these icons should look differently, the latter maybe showing a yellow color or a question mark symbol or similar to denote, that there's an issue rather than trust/security (as a shield icon suggests).

### Version information

- **Platform**: desktop

For the desktop app:

- **OS**: Ubuntu 20.04
- **Version**: 1.7.21

The report includes a screenshot and describes two desktop UI indicators: the room encryption icon and the message authenticity-warning icon. Start by locating the frontend code that renders both indicators; done means they are visibly distinguishable, with the warning state clearly communicating reduced trust, and the relevant UI behavior remains covered.

Written by the indexing model from the issue text.