Allow viewing a specific event in dev tools by event ID

### Your use case

#### What would you like to do?

I would like to inspect a specific event in a room whose event ID I have.

#### Why would you like to do it?

In order to debug all kinds of issues that happen sometimes.

#### How would you like to achieve it?

1. Without scrolling through the entire room history to try to find the event
2. Ideally, with a chat command (`/showevent`?)
3. From the devtools (next to "Send custom timeline event", there should also be "Show timeline event...")

### Have you considered any alternatives?

Sometimes, an `origin_server_ts` is available, which at least makes it possible to scroll to the correct time/date to narrow down the search area.

### Additional context

Maybe this is already possible, but it's not discoverable at all.