Make statusline folder-specific. Update filter, search and threading
status when changing folders.
Commit 2512c04 ("statusline: implement per-account status") introduced
an account-specific statusline. This makes it account- and
folder-specific.
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Tested-by: Moritz Poldrack <moritz@poldrack.dev>
Koni Marti