Chromium Browser: Files didn't open in new tab

[MSoeb]

Description
Files are no longer opened in a tab in Chromium browsers, but are offered for download instead. In comparison, files (here a pdf file) are opened in a new tab in Firefox.

How to Reproduce
Steps to reproduce the behavior:

1. open an instance in a chromium browser
2. open Files
3. upload a pdf file
4. try to open the pdf file

Expected behavior
If possible, files should always be opened in a new browser tab first and not downloaded directly. This should be the general behavior regardless of the browser.

I know, not all file types are supported to be opened in a browser. Please take care, that at least images and pdf files could be opened.

Additional context
Tested in Brave Version 1.68.141 Chromium: 127.0.6533.120 (Offizieller Build) (64-Bit)](https://brave.com/latest/

This issue is basically the same as in OpenSlides/openslides-client#4032. I've discussed the topic with @bastianjoel and we decided to put a concept label on it here, because solving it could result in security issues and it should be discussed if it is doable without a security issue. Also it is not a bug. Currently it is intended behavior.

[bastianjoel]

Introduced by #74