View source – Decrypted event source does not show the actual event

### Steps to reproduce

1. Be in a room with A) a message sent from the current device, and B) a message sent from another device/another account.
2. Via the options for the message, open "View source" for both A) and B).
3. Observe the different fields present for A) and B)in "Decrypted event source".

### Outcome

#### What did you expect?
"Decrypted event source" in "View source" should show the actual event source/plaintext, and with that have the same fields present for both A) and B), since this feature is supposed to be a developer introspection tool.

#### What happened instead?
"Decrypted event source" seems to show some internal representation, not the fields of an actually existent event.
What's shown differs depending on whether the event was sent by the same device that's used for inspection: A) has only `type` and `content, while B) has additional fields `event_id`, `origin_server_ts`, `room_id`, `sender` and `unsigned`.

A)

B)

### Operating system

Arch Linux

### Application version

Element version: 1.12.18, Crypto version: Rust SDK 0.16.0 (65b585f), Vodozemac 0.9.0

### How did you install the app?

via pacman (element-desktop)

### Homeserver

element.io

### Will you send logs?

Yes