Reword Initial Step description

Change to include the word preset and tasks.
Fix update view in Load Data Step

The view didn't update when changing the combobox current node, only when
a new image was added.
Now it's changed everytime a combobox node is changed.
Link slices together on start up

When creating the workflow module GUI, the slices are now automatically
linked together.
Use lowercase suffixes

It improves readibility and is more slicer-like.
Fix weird spacing above Advanced Settings Panel

There was a small gap between the workflow and the advanced settings panel
due to a bad top margin in the advanced settings panel ui.
Also, adding left and right spacing so it's not stuck against the borders
of the application. This is because the prometheus workflow layout doesn't
have any borders.
Add opacity slider

This opacity slider helps to control the opacity of the views' background
and foreground slices.