Use special icons for rooms associated to objects

[Ivansss]

Same as in the web client:
nextcloud/spreed#1346

[mario]

Thanks!

[Ivansss]

Let's use the text icon for files:
nextcloud/spreed#1387

[mario]

@Ivansss where can I find the SVGs for text icon and lock thing?

[Ivansss]

Text icon:
https://github.com/nextcloud/server/blob/master/core/img/filetypes/text.svg

Lock icon:
https://github.com/nextcloud/server/blob/master/core/img/actions/password.svg