Consider removing the attachment screen

### Your use case

I got my family to use Element, and their general impression after 1+ year is that "it doesn't work", at least not reliably.

A major issue seems to be the dark screen with an attachment/link icon that appears when clicking on a non-media attachment.
- It leaves the impression that Element can't "open" PDFs and similar files, while other messaging apps can.
- The unlabeled outgoing link icon in the top right corner isn't easily found, and even then isn't understood to mean open (as opposed to forward or something)

I don't know what positives it offers over just opening the received file, but it does seem to cause friction.

### Have you considered any alternatives?

_No response_

### Additional context

_No response_

### Are you willing to provide a PR?

No