As a user, I can use a filter for selecting a folder of the Test Plan in the Test Plan issue screen

As a user, I can use a filter for selecting a folder of the Test Plan in the Test Plan issue screen, namely in the list of Tests.

If a folder is selected, then only the tests of that Test Plan board folder will be shown by the ranking they have in the Test Plan board. Otherwise, all tests of the Test Plan will be shown.
This filter only appears if the admin setting for hierarchical tests is enabled. In this case, by default, the root of the Test Plan Board is selected. The filter shall also allow the empty choice; in this case it will show all the tests of the Test Plan by the ranking they have in the Test Plan (not the Test Plan Board ranking).

A checkbox should exist in order to show or not all the descendants of a given Test Plan board folder (by default unchecked). In the "user session", the last folder selected must be store and also the value of the checkbox.