Don't leave options set on the remote in one of the unit tests. If
something should be set for every test it should be done in
global_setup(). This commit also changes the FlatpakRemote
implementation to allow unsetting title and default branch.

po: Update Ukrainian translation

transaction: Update get_operations() docs

Document that operations are executed in the same order they are
returned because gnome-software is depending on that:
https://gitlab.gnome.org/GNOME/gnome-software/-/blob/cf5656031f0d25c9c36e2ad0e6e6cfd4b4f2c718/plugins/flatpak/gs-flatpak-transaction.c#L279

This fixes #3636

When --device=all is *not* passed to Flatpak, --dev is passed to bwrap,
which causes it to use an intermediate user namespace to mount devpts
because it can only be mounted as UID 0. Therefore, when expose-pids
is used, Flatpak will pass both --userns *and* --userns2 to handle
the presence of the intermediate namespace.

However, when --device=all *is* passed, there is no intermediate
namespace. Thus, setns(userns2) will fail with EINVAL. In order to
handle this, --userns2 is no longer passed if the namespace is
identical to that passed via --userns.

Fixes #3722.

We already verify that the ref is not installed on add_ref(), so we
did check for "user error". If the transaction either raced with some
other process, or the install from the install-authentitcator signal
that should not be treated as an error.