ui-shared: Preserve path limit in "tab bar" links

ui-shared: Preserve path limit in "tab bar" links

When using the "tab bar" in the pageheader to navigate between pages, any
path limit in effect on the current page is forgotten in the link to the
target page, even if the target page can interpret and use the path limit
constructively.

Instead, preserve the current page's path limit in the "tab bar" links to
other pages, where the path limit is useful to the target page.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>