[Feature Request] Add a "Show all views" option in the Model Tree Filtering options

[AlexisHFr]

Description

While filtering concepts of the model tree, an indirect impact is that all views are filtered out and inaccessible to user.

A more basic option would be to add a 'Show all views' in the same logic with the 'Show all Folders', which is the feature request here.

Another option could be to separate more clearly Views from Concepts/Relationships of the model.. for eg by creating a clone of the Models widget in the UI but dedicated for 'Views' (in my mind I don't think of 'Views' as elements of the model but as projection of the model content for a specific need/viewpoints so merging views with concepts & relationships is not natural for me), but this is a more impactful change .. and something that's rooted in Archi since the early days..