Nemo should show all mounted devices under "Computer", and ONLY mounted devices

[NSExceptional]

Note

I am new to Linux (but not unix; I am an iOS dev), so if there is an easy fix for either of my two suggestions below, I'm unaware. I did my due diligence in trying to solve both of these on my own before making this post :)

---

TLDR: the "Computer" view should behave like it does on Windows and macOS. The majority of desktop users expect a simple, unified view of all their mounted drives and disk images.

I assume the current behavior is legacy convention from multi-user/server environments, but it persists even in Linux consumer desktop environments like this as a result of:

• Inherited conventions from upstream projects (GNOME, udisks2, etc)
• A conservative approach to avoid exposing system-critical mounts by default (most of which aren't a thing in consumer desktop environments)
• Lack of developer focus on the finer "user experience" details such as this

On that same note, I would also like to insist that "Computer" not display raw, unmountable devices (related: #1014). For example, my boot drive shows up twice! Once as the raw device, and again as "File System". It is redundant and confusing. Nemo should try to mimic users' expectations from other established platforms in this domain. This is a file browser, not Disk Utility.app.

In summary, I want the Computer view to:

• Hide "raw devices" (could be addressed by adding a way to "hide" things from Computer (see: Is Nemo supposed to respect `UDISKS_IGNORE`? #1014))
• Show all mounted devices, regardless of whether they're mounted in /media/$USER/ or /mnt/

You can make the case that some users want the existing behavior in both cases, and that's fine. But make let's make it a setting at the very least! I should be able to configure Nemo to behave more or less the way Windows and macOS do in this area :)