Major This scenario is not performed:
1) Open WD.
2) Add "Read sequence" on the scene.
3) Click the element.
Expected state: bottom datasets panel is visible.
4) Add one input file.
Expected state: File's url appears in the list. The element's doc has the blue link to this file.
5) Click on the empty place of the scene.
6) Switch on iterations mode.
7) Click on the element
Expected state: bottom datasets panel is visible. It has one url.
Actual state: Urls list is empty.
