Allow collapse / expand of redactions (deletions)

### Your use case

#### What would you like to do?
Have Element X for Android collapse multiple deleted (redacted) messages into a single expandable “x messages removed” placeholder — the same way Element Web or the classic Android app does.

#### Why would you like to do it?
Currently, when several consecutive messages are deleted, Element X shows a separate “Message removed” line for each one. This quickly clutters the timeline and makes it harder to follow conversation flow. Collapsing them into one expandable group would keep the timeline much cleaner.

#### How would you like to achieve it?
Introduce an automatic collapse/expand mechanism for consecutive redactions:
When multiple deleted messages appear in a row, show one line like “5 messages removed (tap to expand)”
On tap, expand to show individual placeholders if desired.
Match Element Web / Desktop behaviour for consistency across clients.

### Have you considered any alternatives?
None at the moment. The only workaround is to use Element Web / Desktop or the classic client.

### Additional context

### Are you willing to provide a PR?

No