Allow package IncludeWorkflows to be deprecated and hidden from the toolbox

[bruno-f-cruz]

Similarly to C# operators, it would be great to have a way to pass deprecation tags to IncludeWorkflows that are part of packages.

In addition to deprecation tag, a way to hide these operators from the toolbox would also be great!

[glopesdev]

Feedback from DCM: it might be nice to include these attributes as part of common workflow metadata, so we don't have to rely on C# classes.

Another interesting idea from @ncguilbeault was to use a node itself to store these attributes.

Or use logic similar to externalized properties where these properties would show up when clicking the background of the group workflow.

[glopesdev]

If we do extend the set of common attributes on WorkflowBuilder they should all become editable when clicking the top-level workflow, and also be made part of GroupWorkflow properties.