Zoom buttons

[deelman]

Describe the user role

Team black
Describe the goal

add descriptions to the zoom buttons when user hovers over them
Describe the benefit

clarify the role the of buttons, +/- are clear, but the others are not, I am not sure what the 3rd button does, does not seem to do anythign
Additional context

[HaiboNi]

I also found the buttons confusing, especially the button with 4 arrows (looks like full screen). When tested with a minimal example (2 to 5 nodes in the flowchart), pressing the 4-arrow button did not produce any change, even after several zoom-in and out clicks to change the workbench view.