Unified Search Widget lost fitering options on folders opened in its own tabs

[IagoSRL]

Since some Thunderbird versions (15?) in that several interfaces changes were done, one of then was that quick-filter-bar is not shared between the main tab and other folder tabs, and that folder tabs remember its own filtering options independent of the use of the sticky pin when jumping between tabs.

And the bug comes from that, when returning to a folder tab that was filtered, filter is still being applied (because quick filter bar is hidden enabled) but Unified Search Widget show no filter options enabled.