What needs to be fixed

Currently, when no tracker has been defined for a given artidoc, and the user tries to add an existing section to it, the user will not be able to search for artifacts because the auto-completer won't find anything (no tracker).

This behavior exists because we forgot this use-case while implementing story #39369.

Expected behavior

Given an artidoc with no be configuration yet (e.g no tracker is defined)

When the user clicks on the [Add existing section] button

Then we should open the configuration modal first, and open the "add existing section" modal when the configuration has been saved successfully.

Note: This is the current behavior of the [Create new section] button. The two behaviors should be aligned.