[Story] U-08C: DM room header shows Bob's identity change

### Description

As Alice
When I am sending message to Bob in our DM room
And we have verified each other with Bob in the past
But Bob's identity has changed after this
Then I want the room header to indicate that Bob's identity has changed
So that it would be consistent with showing previously there that Bob was verified.

Note: this only applies to a DM room with one other participant.

**Designs**
* [iOS](https://www.figma.com/design/0oUTCbYhROEDprSp7bdWhx/Identity-Changes?node-id=1606-39739&t=u3djDFGxksLmI0Qt-4) | [Android](https://www.figma.com/design/0oUTCbYhROEDprSp7bdWhx/Identity-Changes?node-id=1606-32498&t=u3djDFGxksLmI0Qt-4) | [Web](https://www.figma.com/design/gpxHFDTNK796n84r1ZxYG2/Room-Header-%26-Details-(2024)?node-id=85-116716&t=17IULBxiS33mHNLh-4)

### Acceptance criteria

- TBD

### Size estimate

None

### Dependencies

- None

### Out of scope

- Nothing

### Open questions

```[tasklist]
### Questions
```

### Subtasks

```[tasklist]
### Android
- [ ] Todo
```

```[tasklist]
### iOS
- [x] Room header shows decoration when Bob's verified-identity has changed
```

```[tasklist]
### Rust
```

```[tasklist]
### Web
- [x] Room header shows decoration when Bob's verified-identity has changed
- [ ] The tooltip of the decoration should show "Verified identity has changed" instead of "Untrusted"
- [ ] When "exclude insecure devices" FF is turned ON: do not show the decoration in case Bob has unverified device
```