Existing pipeline object doesn't display at the library-tree panel

__NOTE__: Such behavior doesn't appear constantly, "flaky" bug.

1. Open "Library" page
2. Hover over "+ Create v" button
3. In an appeared list select "Pipeline" > "SHELL" item
4. In an appeared pop-up specify a valid pipeline name
5. Click "CREATE" button

__*Exp.*__: just-created pipeline object is displayed in the left library-tree panel and in the right panel
__*Act.*__: just-created pipeline object is displayed only in the right panel and isn't displayed in the left library-tree panel

The bug is discovered by e2e-tests, an example of such behavior:

Reproduce the issue from the Library page using the Create > Pipeline > SHELL flow, then compare the left library-tree panel with the right panel after creation. Start by locating the e2e test that discovered this behavior and use it to trace the library-tree update path. Done means the created pipeline appears in both panels and the flaky case has a regression test.

Written by the indexing model from the issue text.