Apparently duplicate remotes, unclear that some are system-wide while disabled

[x] I have read the README.md document
[x] I am using the latest version of Warehouse
[x] I am using the Flatpak package of Warehouse
[x] I have not found any other opened issues on the same topic

Describe the issue in detail

There is some discrepancy between the GUI and terminal here, that led me to much confusion on my desktop computer:

You can see three remotes called "Flathub" there, and:

It is not clear that the disabled one is a "system" one (instead of user-wide)
There are two user-wide "Flathub" remotes, which is really weird

The result as a user is that I am scared to remove any of them.

flatpak remotes lists:

Name                     Options
flathub                  user
flathub-beta             user
gnome-nightly            user
webkit                   user

I have to run flatpak remotes --show-disabled to finally understand what was going on with the yellow disabled "Flathub" remote, it turns out it's a system remote:

Name                     Options
fedora-testing           system,disabled,oci
flathub                  system,disabled,filtered
flathub                  user
flathub-beta             user
gnome-nightly            user
webkit                   user

But:

The UI doesn't make that clear, because it just shows the "Disabled" sublabel. Shouldn't it show "System remote — Disabled" instead?
It does not have a duplicate user-wide "flathub" remote, but the GUI does. Even if "Show Disabled" is not active:

Run `flatpak run io.github.flattool.Warehouse` in a terminal and if applicable, show any output

On startup I immediately get this traceback (a bit similar to #127, but not exactly?) :

Traceback (most recent call last):
  File "/app/share/warehouse/flattool_gui/window.py", line 940, in <lambda>
    lambda *_: GLib.idle_add(lambda *_: self.generate_list_of_flatpaks())
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/share/warehouse/flattool_gui/window.py", line 328, in generate_list_of_flatpaks
    self.host_flatpaks = self.my_utils.get_host_flatpaks()
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/share/warehouse/flattool_gui/common.py", line 190, in get_host_flatpaks
    data[i].append(lines[i])
                   ~~~~~^^^
IndexError: list index out of range

…with this broken GUI:

flattool / warehouse