COMP: Bump Slicer version to integrate latest SlicerExecutionModel

By default, Slicer uses SlicerExecutionModel's FindJsonCpp which was
lacking behind TubeTK's. The SlicerExecutionModel's FindJsonCpp was updated
and Slicer pulls the latest version of the SlicerExecutionModel.
ENH: Improve prometheus workflow

Harmonize the workflow name, add an icon and make it the default home
module.
ENH: Support 1 to 3 input in LoadData step
ENH: Improve view update for the workflow

Instead of relying on an internal map of volumes, it is much better to
use the selection node. Since it already keeps track of the volumes
displayed, we can use it to make sure we are on sync with them.
The update is now automatically called when the selection node is modified.
ENH: Support 1 to 3 inputs in Register step

In order to reduce code redundancy, the register step was separated in
a widget and a step itself. The widget is not much different than the
old step as it's in charge of running the CLI.
The step is now in charge of instantiating the necessary widgets and make
sure to validate them correctly.
ENH: Make registration type available in intermediate workflow
ENH: Improve icons
ENH: Update Resample Step to handle 1 to 3 inputs
ENH: Collapse the data probe automatically
ENH: Resample step before Register step

It is better to resample the volume 2 and 3 during the registration. To
this end, we switch the resample step and the register step. The resampling
is consequently only done on the first volume.
ENH: Improve segmentation Step to allow an easier editing interface
ENH: Create an adaptive layout

Create a different layout when dealing with 1, 2 or 3 inputs. This layout
is update through the use of the setViews method.
The workflow keeps track of all the volume displayed to make sure that
added volumes aren't shown after a setView update.
It also take care of enabling/showing the opacity slider whenever a slice
has more than one image displayed.

WIP
ENH: Remove unecessary Register widget parameters
ENH: Add comboboxes for additionnal input parameters to the PDF segmenter
ENH: Refactor vessel enahncement step to use the correct cli
Merge remote-tracking branch 'githubOrigin/workflow'

* githubOrigin/workflow:
  ENH: Refactor vessel enahncement step to use the correct cli
  ENH: Add comboboxes for additionnal input parameters to the PDF segmenter
  ENH: Remove unecessary Register widget parameters
  ENH: Create an adaptive layout
  ENH: Improve segmentation Step to allow an easier editing interface
  ENH: Resample step before Register step
  ENH: Collapse the data probe automatically
  ENH: Update Resample Step to handle 1 to 3 inputs
  ENH: Improve icons
  ENH: Make registration type available in intermediate workflow
  ENH: Support 1 to 3 inputs in Register step
  ENH: Improve view update for the workflow
  ENH: Support 1 to 3 input in LoadData step
  ENH: Improve prometheus workflow
  COMP: Bump Slicer version to integrate latest SlicerExecutionModel