Improvements to parent filters

As a user, I need a better experience in delivery plans to see all my work by one or more parents. I should be able to select multiple parent work items across all teams.

Initial state, an empty "filter by parent" search box with no parent selected.

See all available parents relative to the teams and backlog levels.

Once one or more parents are selected (filter is active), we show the checkbox asking if you want to see the hierarchy view.

Introduce a menu on the work items, that when clicked, will apply the parent filter across all teams.