GUI: DPU tree panel is not properly redrawn

[tomas-knap]

When hiding or opening the basic information about pipeline in pipeline edit window, the DPU tree is NOT correctly redrawn.

To reproduce:

1. Open any pipeline
2. click on the button to hide the name/description. Do not move mouse. Result is:

3. move with the mouse. Only at that moment the DPU tree is moved.

THis is wrong, DPU tree must be redrawn when the button for hide/reveal of the description is pressed.

Tested on develop branch, commit 1128928

[mvi-eea-sk]

fixed: 0be277e