Napari-time-slicer

Bug fixes
* Zombie tasks that have no result layer anymore are removed automatically
* If a parameter list contained a default parameter of type function it is removed to improve generated code quality

Backwards compatiblity breaking changes
* The `WorkflowWidget` was moved to napari-workflow-inspector

Bugfix:
* Show workflow intermediate result images from top left to bottom right in grid view

New features
* Workflow Viewer in menu Tool > Visualization to see the current state of the image data flow graph
* Code generation

Bug fixes
* Internally less events are used and a central Workflow-manager instead. This should make things more stable
* The system remains funcitonal when input-data is changed or layers are removed and added

documentation update

Bug fixes
* In case the Z-dimension of a 4D image has only one plane, provide a 2D image instead of 3D with one plane